题解 | #大数加法#

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     * 计算两个数之和
     * @param s string字符串 表示第一个整数
     * @param t string字符串 表示第二个整数
     * @return string字符串
     */
    public String solve (String s, String t) {
        // write code here
        // write code here
        StringBuilder builder = new StringBuilder("");
        int j = 0;
        int num1 = 0;
        int num2 = 0;
        int sLength = s.length() - 1;
        int tLength = t.length() - 1;
        while (sLength >= -1 || tLength >= -1) {
            if (sLength <= -1 && tLength <= -1 && j == 0) break;
            if (sLength >= 0) num1 = s.charAt(sLength) - 48;
            else num1 = 0;
            if (tLength >= 0) num2 = t.charAt(tLength) - 48;
            else num2 = 0;
            builder.insert(0, (num1 + num2 + j) % 10 + "");
            j = (num1 + num2 + j) / 10;
            sLength--;
            tLength--;
        }
        return builder.toString();
    }
}