题解 | #大数加法#

class Solution:
    def solve(self, s: str, t: str) -> str:
        # write code here
        if s == "0":
            return t
        if t == "0":
            return s
        idx1, idx2 = len(s) - 1, len(t) - 1
        carry = 0
        res = ""
        while idx1 >= 0 or idx2 >= 0 or carry:
            if idx1 >= 0:
                carry += int(s[idx1])
                idx1 -= 1
            if idx2 >= 0:
                carry += int(t[idx2])
                idx2 -= 1
            res += str(carry % 10)
            carry //= 10
        return res[::-1]