leetcode-javascript/solutions/0844-backspace-string-compare.js at development · Anuj9826/leetcode-javascript · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
/**
 * Backspace String Compare
 * Time Complexity: O(lengthS + lengthT)
 * Space Complexity: O(1)
 */
var backspaceCompare = function (stringOne, stringTwo) {
  let currentPointerOne = stringOne.length - 1;
  let currentPointerTwo = stringTwo.length - 1;

  while (currentPointerOne >= 0 || currentPointerTwo >= 0) {
    let backspaceCountOne = 0;
    while (currentPointerOne >= 0) {
      if (stringOne[currentPointerOne] === "#") {
        backspaceCountOne++;
        currentPointerOne--;
      } else if (backspaceCountOne > 0) {
        backspaceCountOne--;
        currentPointerOne--;
      } else {
        break;
      }
    }

    let backspaceCountTwo = 0;
    while (currentPointerTwo >= 0) {
      if (stringTwo[currentPointerTwo] === "#") {
        backspaceCountTwo++;
        currentPointerTwo--;
      } else if (backspaceCountTwo > 0) {
        backspaceCountTwo--;
        currentPointerTwo--;
      } else {
        break;
      }
    }

    const resolvedCharOne =
      currentPointerOne >= 0 ? stringOne[currentPointerOne] : null;
    const resolvedCharTwo =
      currentPointerTwo >= 0 ? stringTwo[currentPointerTwo] : null;

    if (resolvedCharOne !== resolvedCharTwo) {
      return false;
    }

    if (currentPointerOne >= 0) {
      currentPointerOne--;
    }
    if (currentPointerTwo >= 0) {
      currentPointerTwo--;
    }
  }

  return true;
};