Add Binary

main.md

Question

Approach

1. using binary addition i start adding from the least significant bit at the endof the string.
2. carry variable stores overload from addition of bits in binary and adds it to the sum of the nexts bits while the loop continues.
3. remainder of bits is added to the end of a result array which is returned as a string

Complexity

• Time complexity:O(Max(A,B))

• Space complexity:O(Max(A,B))

Code

function addBinary(a: string, b: string): string {
    let i = a.length - 1;
    let j = b.length - 1;
    let carry = 0;
    let result = [];

    while (i >= 0 || j >= 0 || carry) {
        let sum = carry;

        if (i >= 0) sum += Number(a[i--]);
        if (j >= 0) sum += Number(b[j--]);

        result.unshift(sum % 2);
        carry = Math.floor(sum / 2);
    }

    return result.join("");
}