From e5dd271d687b32e26540ece98756781149bbb916 Mon Sep 17 00:00:00 2001 From: Zobeir-Rigi Date: Thu, 19 Mar 2026 15:28:50 +0000 Subject: [PATCH 1/9] ls done --- individual-shell-tools/ls/script-01.sh | 4 ++++ individual-shell-tools/ls/script-02.sh | 2 ++ individual-shell-tools/ls/script-03.sh | 1 + individual-shell-tools/ls/script-04.sh | 3 ++- 4 files changed, 9 insertions(+), 1 deletion(-) diff --git a/individual-shell-tools/ls/script-01.sh b/individual-shell-tools/ls/script-01.sh index 241b62f5e..f21b021b0 100755 --- a/individual-shell-tools/ls/script-01.sh +++ b/individual-shell-tools/ls/script-01.sh @@ -13,3 +13,7 @@ fi # TODO: Write a command to list the files and folders in this directory. # The output should be a list of names including child-directory, script-01.sh, script-02.sh, and more. + +#I'm in the current folder, And I used cd, now just need to use ls + +ls diff --git a/individual-shell-tools/ls/script-02.sh b/individual-shell-tools/ls/script-02.sh index d0a5a10f4..e0de21994 100755 --- a/individual-shell-tools/ls/script-02.sh +++ b/individual-shell-tools/ls/script-02.sh @@ -4,3 +4,5 @@ set -euo pipefail # TODO: Write a command which lists all of the files in the directory named child-directory. # The output should be a list of names: helper-1.txt, helper-2.txt, helper-3.txt. + +ls child-directory \ No newline at end of file diff --git a/individual-shell-tools/ls/script-03.sh b/individual-shell-tools/ls/script-03.sh index 781216d21..7a1a1d315 100755 --- a/individual-shell-tools/ls/script-03.sh +++ b/individual-shell-tools/ls/script-03.sh @@ -5,3 +5,4 @@ set -euo pipefail # TODO: Write a command which _recursively_ lists all of the files and folders in this directory _and_ all of the files inside those folders. # The output should be a list of names including: child-directory, script-01.sh, helper-1.txt (and more). # The formatting of the output doesn't matter. +ls -R \ No newline at end of file diff --git a/individual-shell-tools/ls/script-04.sh b/individual-shell-tools/ls/script-04.sh index 72f3817b3..ad9dc5d2a 100755 --- a/individual-shell-tools/ls/script-04.sh +++ b/individual-shell-tools/ls/script-04.sh @@ -15,9 +15,10 @@ echo "First exercise (sorted newest to oldest):" # TODO: Write a command which lists the files in the child-directory directory, one per line, sorted so that the most recently modified file is first. # The output should be a list of names in this order, one per line: helper-3.txt, helper-1.txt, helper-2.txt. - +ls -1t child-directory echo "Second exercise (sorted oldest to newest):" # TODO: Write a command which does the same as above, but sorted in the opposite order (oldest first). # The output should be a list of names in this order, one per line: helper-2.txt, helper-1.txt, helper-3.txt. +ls -1tr child-directory \ No newline at end of file From 0a88ee6ed9a20593424dd0a9522b30f6013d8584 Mon Sep 17 00:00:00 2001 From: Zobeir-Rigi Date: Thu, 19 Mar 2026 17:09:36 +0000 Subject: [PATCH 2/9] cat done --- individual-shell-tools/cat/script-01.sh | 2 ++ individual-shell-tools/cat/script-02.sh | 2 ++ individual-shell-tools/cat/script-03.sh | 1 + individual-shell-tools/cat/script-04-stretch.sh | 1 + 4 files changed, 6 insertions(+) diff --git a/individual-shell-tools/cat/script-01.sh b/individual-shell-tools/cat/script-01.sh index c85053e0f..ba802a7b1 100755 --- a/individual-shell-tools/cat/script-01.sh +++ b/individual-shell-tools/cat/script-01.sh @@ -4,3 +4,5 @@ set -euo pipefail # TODO: Write a command to output the contents of the helper-1.txt file inside the helper-files directory to the terminal. # The output of this command should be "Once upon a time...". + cd helper-files + cat helper-1.txt \ No newline at end of file diff --git a/individual-shell-tools/cat/script-02.sh b/individual-shell-tools/cat/script-02.sh index 01bbd5eab..5ebad5846 100755 --- a/individual-shell-tools/cat/script-02.sh +++ b/individual-shell-tools/cat/script-02.sh @@ -11,3 +11,5 @@ set -euo pipefail # It looked delicious. # I was tempted to take a bite of it. # But this seemed like a bad idea... +cat *.txt +pwd should be in the helper-files directory diff --git a/individual-shell-tools/cat/script-03.sh b/individual-shell-tools/cat/script-03.sh index 37573b0c1..15b907147 100755 --- a/individual-shell-tools/cat/script-03.sh +++ b/individual-shell-tools/cat/script-03.sh @@ -9,3 +9,4 @@ set -euo pipefail # 1 It looked delicious. # 2 I was tempted to take a bite of it. # 3 But this seemed like a bad idea... +cat -n helper-3.txt \ No newline at end of file diff --git a/individual-shell-tools/cat/script-04-stretch.sh b/individual-shell-tools/cat/script-04-stretch.sh index 00fe3c48b..b88e84c52 100755 --- a/individual-shell-tools/cat/script-04-stretch.sh +++ b/individual-shell-tools/cat/script-04-stretch.sh @@ -13,3 +13,4 @@ set -euo pipefail # 3 It looked delicious. # 4 I was tempted to take a bite of it. # 5 But this seemed like a bad idea... +cat * | nl \ No newline at end of file From c6d213f124e1cc510c9f8eaa9b61e8e5d412294e Mon Sep 17 00:00:00 2001 From: Zobeir-Rigi Date: Thu, 19 Mar 2026 17:20:41 +0000 Subject: [PATCH 3/9] wcdone --- individual-shell-tools/wc/script-01.sh | 3 +++ individual-shell-tools/wc/script-02.sh | 1 + individual-shell-tools/wc/script-03.sh | 4 ++++ 3 files changed, 8 insertions(+) diff --git a/individual-shell-tools/wc/script-01.sh b/individual-shell-tools/wc/script-01.sh index c9dd6e5df..878262a25 100755 --- a/individual-shell-tools/wc/script-01.sh +++ b/individual-shell-tools/wc/script-01.sh @@ -4,3 +4,6 @@ set -euo pipefail # TODO: Write a command to output the number of words in the file helper-files/helper-3.txt. # The output should include the number 19. The output should not include the number 92. + +wc -w helper-3.txt +w should be in lowercase, otherwaise you will get illigal option error. diff --git a/individual-shell-tools/wc/script-02.sh b/individual-shell-tools/wc/script-02.sh index 8feeb1a62..a3c0be3c7 100755 --- a/individual-shell-tools/wc/script-02.sh +++ b/individual-shell-tools/wc/script-02.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output the number of lines in the file helper-files/helper-3.txt. # The output should include the number 3. The output should not include the number 19. +wc -l helper-3.txt \ No newline at end of file diff --git a/individual-shell-tools/wc/script-03.sh b/individual-shell-tools/wc/script-03.sh index 6b2e9d3d1..be9d1f6b3 100755 --- a/individual-shell-tools/wc/script-03.sh +++ b/individual-shell-tools/wc/script-03.sh @@ -8,3 +8,7 @@ set -euo pipefail # 1 7 39 ../helper-files/helper-2.txt # 3 19 92 ../helper-files/helper-3.txt # 5 30 151 total + +wc -lwm * +I am in the directory(helper-files) + From 983c6ab61191a869c6e6aa88d2bf323246d5502d Mon Sep 17 00:00:00 2001 From: Zobeir-Rigi Date: Thu, 19 Mar 2026 18:49:09 +0000 Subject: [PATCH 4/9] grep done --- individual-shell-tools/grep/script-01.sh | 1 + individual-shell-tools/grep/script-02.sh | 1 + individual-shell-tools/grep/script-03.sh | 2 ++ individual-shell-tools/grep/script-04.sh | 1 + individual-shell-tools/grep/script-05.sh | 1 + individual-shell-tools/grep/script-06.sh | 1 + individual-shell-tools/grep/script-07.sh | 1 + 7 files changed, 8 insertions(+) diff --git a/individual-shell-tools/grep/script-01.sh b/individual-shell-tools/grep/script-01.sh index fb05f42f2..72cd51b58 100755 --- a/individual-shell-tools/grep/script-01.sh +++ b/individual-shell-tools/grep/script-01.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output every line in dialogue.txt said by the Doctor. # The output should contain 6 lines. +grep "^Doctor:" dialogue.txt \ No newline at end of file diff --git a/individual-shell-tools/grep/script-02.sh b/individual-shell-tools/grep/script-02.sh index df6f85640..0d801d794 100755 --- a/individual-shell-tools/grep/script-02.sh +++ b/individual-shell-tools/grep/script-02.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output every line in dialogue.txt that contains the word Doctor (regardless of case). # The output should contain 9 lines. +grep -ci "Doctor" dialogue.txt \ No newline at end of file diff --git a/individual-shell-tools/grep/script-03.sh b/individual-shell-tools/grep/script-03.sh index 5383fe578..69cfc760e 100755 --- a/individual-shell-tools/grep/script-03.sh +++ b/individual-shell-tools/grep/script-03.sh @@ -4,3 +4,5 @@ set -euo pipefail # TODO: Write a command to output the number of lines in dialogue.txt that contain the word Doctor (regardless of case). # The output should be exactly the number 9. +grep -ci "Doctor" dialogue.txt + diff --git a/individual-shell-tools/grep/script-04.sh b/individual-shell-tools/grep/script-04.sh index 80ee04776..392ff8d8f 100755 --- a/individual-shell-tools/grep/script-04.sh +++ b/individual-shell-tools/grep/script-04.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output every line in dialogue.txt that does not contain the word "Hello" (regardless of case). # The output should contain 10 lines. +grep -vi "Hello" dialogue.txt \ No newline at end of file diff --git a/individual-shell-tools/grep/script-05.sh b/individual-shell-tools/grep/script-05.sh index 1eb538185..a7e28a473 100755 --- a/individual-shell-tools/grep/script-05.sh +++ b/individual-shell-tools/grep/script-05.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output every line in dialogue.txt that contains the string "cure", as well as the line before that line. # The output should contain two pairs of two lines of text (with a separator between them). +grep -B 1 "cure" dialogue.txt \ No newline at end of file diff --git a/individual-shell-tools/grep/script-06.sh b/individual-shell-tools/grep/script-06.sh index 5670e3b6c..87c9d9e93 100755 --- a/individual-shell-tools/grep/script-06.sh +++ b/individual-shell-tools/grep/script-06.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output the name of every `.txt` file in this directory which contains a line of dialogue said by the Doctor. # The output should contain two filenames. +grep -l "Doctor" *.txt \ No newline at end of file diff --git a/individual-shell-tools/grep/script-07.sh b/individual-shell-tools/grep/script-07.sh index 9670ebad9..0ef496e49 100755 --- a/individual-shell-tools/grep/script-07.sh +++ b/individual-shell-tools/grep/script-07.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output, for each `.txt` file in this directory, how many lines of dialogue the Doctor has. # The output should show that dialogue.txt contains 6 lines, dialogue-2.txt contains 2, and dialogue-3.txt contains 0. +grep -c "Doctor" *.txt \ No newline at end of file From 2164c5e757358227c922b6d1619fc91ee8cc66da Mon Sep 17 00:00:00 2001 From: Zobeir-Rigi Date: Fri, 20 Mar 2026 13:41:33 +0000 Subject: [PATCH 5/9] sed done, I feel two last scripts are difficult --- individual-shell-tools/sed/script-01.sh | 2 ++ individual-shell-tools/sed/script-02.sh | 1 + individual-shell-tools/sed/script-03.sh | 1 + individual-shell-tools/sed/script-04.sh | 1 + individual-shell-tools/sed/script-05.sh | 1 + individual-shell-tools/sed/script-06.sh | 1 + 6 files changed, 7 insertions(+) diff --git a/individual-shell-tools/sed/script-01.sh b/individual-shell-tools/sed/script-01.sh index d592970fc..0bd78a317 100755 --- a/individual-shell-tools/sed/script-01.sh +++ b/individual-shell-tools/sed/script-01.sh @@ -5,3 +5,5 @@ set -euo pipefail # TODO: Write a command to output input.txt with all occurrences of the letter `i` replaced with `I`. # The output should contain 11 lines. # The first line of the output should be: "ThIs Is a sample fIle for experImentIng wIth sed.". + +sed 's/i/I/g' input.txt \ No newline at end of file diff --git a/individual-shell-tools/sed/script-02.sh b/individual-shell-tools/sed/script-02.sh index abdd64d06..76576ecb8 100755 --- a/individual-shell-tools/sed/script-02.sh +++ b/individual-shell-tools/sed/script-02.sh @@ -5,3 +5,4 @@ set -euo pipefail # TODO: Write a command to output input.txt with numbers removed. # The output should contain 11 lines. # Line 6 of the output should be " Alisha". +sed 's/[0-9]//g' input.txt] \ No newline at end of file diff --git a/individual-shell-tools/sed/script-03.sh b/individual-shell-tools/sed/script-03.sh index dd284a296..0f5779306 100755 --- a/individual-shell-tools/sed/script-03.sh +++ b/individual-shell-tools/sed/script-03.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output input.txt removing any line which contains a number. # The output should contain 6 lines. +sed '/[0-9]/d' input.txt diff --git a/individual-shell-tools/sed/script-04.sh b/individual-shell-tools/sed/script-04.sh index 0052ac6c4..478211422 100755 --- a/individual-shell-tools/sed/script-04.sh +++ b/individual-shell-tools/sed/script-04.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output input.txt replacing every occurrence of the string "We'll" with "We will". # The output should contain 11 lines. +sed "s/We'll/We will/g" input.txt \ No newline at end of file diff --git a/individual-shell-tools/sed/script-05.sh b/individual-shell-tools/sed/script-05.sh index 2dcc91a0c..68582b6b8 100755 --- a/individual-shell-tools/sed/script-05.sh +++ b/individual-shell-tools/sed/script-05.sh @@ -6,3 +6,4 @@ set -euo pipefail # If a line starts with a number and a space, make the line instead end with a space and the number. # So line 6 which currently reads "37 Alisha" should instead read "Alisha 37". # The output should contain 11 lines. +sed -E 's/^([0-9]+) (.*)/\2 \1/' input.txt diff --git a/individual-shell-tools/sed/script-06.sh b/individual-shell-tools/sed/script-06.sh index 0b9390170..6882c3dd0 100755 --- a/individual-shell-tools/sed/script-06.sh +++ b/individual-shell-tools/sed/script-06.sh @@ -8,3 +8,4 @@ set -euo pipefail # The output should contain 11 lines. # Line 3 should be "It contains many lines, and there are some things you may want to do with each of them.". # Line 11 should be "We also should remember, when we go shopping, to get 4 items: oranges, cheese, bread, olives.". +sed -E 's/,([^ ])/,\ \1/g' input.txt From b59cbfeb6008614a09c8bd46c45e0088e6975a4b Mon Sep 17 00:00:00 2001 From: Zobeir-Rigi Date: Fri, 20 Mar 2026 14:08:27 +0000 Subject: [PATCH 6/9] awk done --- individual-shell-tools/awk/script-01.sh | 1 + individual-shell-tools/awk/script-02.sh | 1 + individual-shell-tools/awk/script-03.sh | 1 + individual-shell-tools/awk/script-04.sh | 2 ++ individual-shell-tools/awk/script-05.sh | 2 ++ individual-shell-tools/awk/script-06-stretch.sh | 2 ++ individual-shell-tools/awk/script-07-stretch.sh | 1 + 7 files changed, 10 insertions(+) diff --git a/individual-shell-tools/awk/script-01.sh b/individual-shell-tools/awk/script-01.sh index 8db4390af..90e2397d6 100755 --- a/individual-shell-tools/awk/script-01.sh +++ b/individual-shell-tools/awk/script-01.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output just the names of each player in `scores-table.txt`. # Your output should contain 6 lines, each with just one word on it. +awk '{print $1}' scores-table.txt diff --git a/individual-shell-tools/awk/script-02.sh b/individual-shell-tools/awk/script-02.sh index 5956be9bd..507d07795 100755 --- a/individual-shell-tools/awk/script-02.sh +++ b/individual-shell-tools/awk/script-02.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output the names of each player, as well as their city. # Your output should contain 6 lines, each with two words on it, separated by a space. + awk '{print $1, $2}' scores-table.txt \ No newline at end of file diff --git a/individual-shell-tools/awk/script-03.sh b/individual-shell-tools/awk/script-03.sh index af7c6e8b9..e6dfa1788 100755 --- a/individual-shell-tools/awk/script-03.sh +++ b/individual-shell-tools/awk/script-03.sh @@ -5,3 +5,4 @@ set -euo pipefail # TODO: Write a command to output just the names of each player along with the score from their first attempt. # Your output should contain 6 lines, each with one word and one number on it. # The first line should be "Ahmed 1". +awk '{print $1, $3}' scores-table.txt \ No newline at end of file diff --git a/individual-shell-tools/awk/script-04.sh b/individual-shell-tools/awk/script-04.sh index bf15703c7..111337543 100755 --- a/individual-shell-tools/awk/script-04.sh +++ b/individual-shell-tools/awk/script-04.sh @@ -5,3 +5,5 @@ set -euo pipefail # TODO: Write a command to output just the names of each player in London along with the score from their last attempt. # Your output should contain 3 lines, each with one word and one number on it. # The first line should be "Ahmed 4". +awk '$2=="London" {print $1, $NF}' scores-table.txt +#$NF → last column \ No newline at end of file diff --git a/individual-shell-tools/awk/script-05.sh b/individual-shell-tools/awk/script-05.sh index d1680cb02..dbee2cfb7 100755 --- a/individual-shell-tools/awk/script-05.sh +++ b/individual-shell-tools/awk/script-05.sh @@ -5,3 +5,5 @@ set -euo pipefail # TODO: Write a command to output just the names of each player along with the number of times they've played the game. # Your output should contain 6 lines, each with one word and one number on it. # The first line should be "Ahmed 3". +awk '{print $1, NF-2}' scores-table.txt +# NF = total number of fields in the line, NF - 2 = removes name + city \ No newline at end of file diff --git a/individual-shell-tools/awk/script-06-stretch.sh b/individual-shell-tools/awk/script-06-stretch.sh index 0201e6378..413a35e3f 100755 --- a/individual-shell-tools/awk/script-06-stretch.sh +++ b/individual-shell-tools/awk/script-06-stretch.sh @@ -6,3 +6,5 @@ set -euo pipefail # TODO: Write a command to output the total of adding together all players' first scores. # Your output should be exactly the number 54. +awk '{sum += $3} END {print sum}' scores-table.txt +#sum += $3 → adds each player’s first score diff --git a/individual-shell-tools/awk/script-07-stretch.sh b/individual-shell-tools/awk/script-07-stretch.sh index 3f7155880..0e21b17a8 100755 --- a/individual-shell-tools/awk/script-07-stretch.sh +++ b/individual-shell-tools/awk/script-07-stretch.sh @@ -7,3 +7,4 @@ set -euo pipefail # TODO: Write a command to output just the names of each player along with the total of adding all of that player's scores. # Your output should contain 6 lines, each with one word and one number on it. # The first line should be "Ahmed 15". The second line should be "Basia 37" +awk '{sum=0; for(i=3;i<=NF;i++) sum+=$i; print $1, sum}' scores-table.txt \ No newline at end of file From 62876b02c1f0c869845c6e6174ad87b91d1deb9b Mon Sep 17 00:00:00 2001 From: Zobeir-Rigi Date: Fri, 20 Mar 2026 15:48:44 +0000 Subject: [PATCH 7/9] number systems done --- number-systems/README.md | 43 ++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 21 deletions(-) diff --git a/number-systems/README.md b/number-systems/README.md index 77a3bde94..c1cf52131 100644 --- a/number-systems/README.md +++ b/number-systems/README.md @@ -5,61 +5,62 @@ Do not convert any binary numbers to decimal when solving a question unless the The goal of these exercises is for you to gain an intuition for binary numbers. Using tools to solve the problems defeats the point. Convert the decimal number 14 to binary. -Answer: +Answer: 1110 Convert the binary number 101101 to decimal: -Answer: +Answer: 32+8+4+1 = 45 Which is larger: 1000 or 0111? -Answer: +Answer: 1000 Which is larger: 00100 or 01011? -Answer: +Answer: 01011 What is 10101 + 01010? -Answer: +Answer: 11111 What is 10001 + 10001? -Answer: +Answer: 100010 What's the largest number you can store with 4 bits, if you want to be able to represent the number 0? -Answer: +Answer: 15 How many bits would you need in order to store the numbers between 0 and 255 inclusive? -Answer: +Answer: 2^8 = 255 so 8 bits How many bits would you need in order to store the numbers between 0 and 3 inclusive? -Answer: - +Answer: 2^2=4 2 bits How many bits would you need in order to store the numbers between 0 and 1000 inclusive? -Answer: +Answer: 2^10 = 1024 so 10 bits How can you test if a binary number is a power of two (e.g. 1, 2, 4, 8, 16, ...)? -Answer: +Answer: It's a power of 2 when it had only one 1 Convert the decimal number 14 to hex. -Answer: +Answer: E Convert the decimal number 386 to hex. -Answer: +Answer: 182 Convert the hex number 386 to decimal. -Answer: +Answer: 3*16^2 + 8*16^1 + 6*16^0 = 902 Convert the hex number B to decimal. -Answer: +Answer: 11 If reading the byte 0x21 as a number, what decimal number would it mean? -Answer: +Answer: 2×16^1 + 1×16^0 33 If reading the byte 0x21 as an ASCII character, what character would it mean? -Answer: +Answer: Should be converted to Decimal then ASCII code 33 : ! If reading the byte 0x21 as a greyscale colour, as described in "Approaches for Representing Colors and Images", what colour would it mean? -Answer: +Answer: A very dark grey (almost black), because 0 = black, 255 = white, and 33 is very low in (0-255) If reading the bytes 0xAA00FF as an RGB colour, as described in "Approaches for Representing Colors and Images", what colour would it mean? -Answer: +Answer: Purple , because no green, and full blue If reading the bytes 0xAA00FF as a sequence of three one-byte decimal numbers, what decimal numbers would they be? -Answer: +Answer: AA = 170 +00 = 0 +FF = 255 From 77b4e34c50572844f7c22865526c403b24663587 Mon Sep 17 00:00:00 2001 From: Zobeir-Rigi Date: Fri, 20 Mar 2026 16:12:24 +0000 Subject: [PATCH 8/9] just making a pr in a separate branch --- individual-shell-tools/awk/script-01.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/individual-shell-tools/awk/script-01.sh b/individual-shell-tools/awk/script-01.sh index 90e2397d6..a4ae27032 100755 --- a/individual-shell-tools/awk/script-01.sh +++ b/individual-shell-tools/awk/script-01.sh @@ -4,4 +4,4 @@ set -euo pipefail # TODO: Write a command to output just the names of each player in `scores-table.txt`. # Your output should contain 6 lines, each with just one word on it. -awk '{print $1}' scores-table.txt +awk '{print $1}' scores-table.txt From ae2c162dd70f382c06dac050f0cf10af49f3a8bd Mon Sep 17 00:00:00 2001 From: Zobeir-Rigi Date: Fri, 20 Mar 2026 16:55:46 +0000 Subject: [PATCH 9/9] This Pr should be only about shell tools --- number-systems/README.md | 66 ---------------------------------------- 1 file changed, 66 deletions(-) delete mode 100644 number-systems/README.md diff --git a/number-systems/README.md b/number-systems/README.md deleted file mode 100644 index c1cf52131..000000000 --- a/number-systems/README.md +++ /dev/null @@ -1,66 +0,0 @@ -Do not use any tools or programming to solve these problems. Work it out yourself by hand, and fill in the answers. - -Do not convert any binary numbers to decimal when solving a question unless the question explicitly tells you to. - -The goal of these exercises is for you to gain an intuition for binary numbers. Using tools to solve the problems defeats the point. - -Convert the decimal number 14 to binary. -Answer: 1110 - -Convert the binary number 101101 to decimal: -Answer: 32+8+4+1 = 45 - -Which is larger: 1000 or 0111? -Answer: 1000 - -Which is larger: 00100 or 01011? -Answer: 01011 - -What is 10101 + 01010? -Answer: 11111 - -What is 10001 + 10001? -Answer: 100010 - -What's the largest number you can store with 4 bits, if you want to be able to represent the number 0? -Answer: 15 - -How many bits would you need in order to store the numbers between 0 and 255 inclusive? -Answer: 2^8 = 255 so 8 bits - -How many bits would you need in order to store the numbers between 0 and 3 inclusive? -Answer: 2^2=4 2 bits -How many bits would you need in order to store the numbers between 0 and 1000 inclusive? -Answer: 2^10 = 1024 so 10 bits - -How can you test if a binary number is a power of two (e.g. 1, 2, 4, 8, 16, ...)? -Answer: It's a power of 2 when it had only one 1 - -Convert the decimal number 14 to hex. -Answer: E - -Convert the decimal number 386 to hex. -Answer: 182 - -Convert the hex number 386 to decimal. -Answer: 3*16^2 + 8*16^1 + 6*16^0 = 902 - -Convert the hex number B to decimal. -Answer: 11 - -If reading the byte 0x21 as a number, what decimal number would it mean? -Answer: 2×16^1 + 1×16^0 33 - -If reading the byte 0x21 as an ASCII character, what character would it mean? -Answer: Should be converted to Decimal then ASCII code 33 : ! - -If reading the byte 0x21 as a greyscale colour, as described in "Approaches for Representing Colors and Images", what colour would it mean? -Answer: A very dark grey (almost black), because 0 = black, 255 = white, and 33 is very low in (0-255) - -If reading the bytes 0xAA00FF as an RGB colour, as described in "Approaches for Representing Colors and Images", what colour would it mean? -Answer: Purple , because no green, and full blue - -If reading the bytes 0xAA00FF as a sequence of three one-byte decimal numbers, what decimal numbers would they be? -Answer: AA = 170 -00 = 0 -FF = 255