Add Binary Numbers - Amazon Top Interview Questions


Problem Statement :


Given two strings a and b that represent binary numbers, add them and return their sum, also as a string.

The input strings are guaranteed to be non-empty and contain only 1s and 0s.

Constraints

n ≤ 100,000 where n is the length of a
m ≤ 100,000 where m is the length of b

Example 1

Input

a = "1"
b = "1"

Output

"10"

Example 2

Input

a = "111"
b = "1"

Output

"1000"


Solution :



title-img 




                        Solution in C++ :

char to_char(int i) {
    return i + '0';
}

string solve(string a, string b) {
    int m = a.size(), n = b.size(), carry = 0;

    string res;

    for (int i = m - 1, j = n - 1; i >= 0 || j >= 0; --i, --j) {
        int sum = (i >= 0 ? a[i] - '0' : 0) + (j >= 0 ? b[j] - '0' : 0) + carry;

        res = to_char(sum % 2) + res;

        carry = sum / 2;
    }

    if (carry == 1) res = '1' + res;

    return res;
}
                    




                        Solution in Python : 
                            
class Solution:
    def solve(self, a, b):
        return f"{int(a, 2) + int(b, 2):b}"


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