string-problems-cpp/Add_String.cpp at main · adityaPorwal14/string-problems-cpp · 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
#include <iostream>
#include <string>
#include<algorithm>
using namespace std;

string add(string num1, string num2){
    int carry=0, sum;
    string ans;
    int index1 = num1.size()-1;
    int index2 = num2.size()-1;

    while (index2 >= 0)
    {
        sum = (num1[index1] - '0') + (num2[index2] - '0') + carry;
        carry = sum / 10;
        char c = sum%10 + '0';
        ans += c;
        index1--;
        index2--;
    }

    while(index1>=0) {
        sum = (num1[index1] - '0') + carry;
        carry = sum / 10;
        char c = sum%10 + '0';
        ans += c;
        index1--;
    }

    if(carry)
    ans+='1';

    reverse(ans.begin(),ans.end());
    return ans;

}

int main() {
    string num1,num2;
    cin >> num1 >> num2;

    if(num1.size()>=num2.size())
    cout << add(num1,num2);

    else
    cout << add(num2,num1);

}