**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 :

` ````
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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