大数加法（Java）

先推荐一下大佬的博客    很有用    

https://blog.csdn.net/zhsy28/article/details/75644958

A + B Problem II Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 429009    Accepted Submission(s): 83367   Problem Description I have a very simple problem for you. Given two integers A and B, your job is to calculate the Sum of A + B.     Input The first line of the input contains an integer T(1<=T<=20) which means the number of test cases. Then T lines follow, each line consists of two positive integers, A and B. Notice that the integers are very large, that means you should not process them by using 32-bit integer. You may assume the length of each integer will not exceed 1000.     Output For each test case, you should output two lines. The first line is "Case #:", # means the number of the test case. The second line is the an equation "A + B = Sum", Sum means the result of A + B. Note there are some spaces int the equation. Output a blank line between two test cases.     Sample Input   2 1 2 112233445566778899 998877665544332211     Sample Output   Case 1: 1 + 2 = 3 Case 2: 112233445566778899 + 998877665544332211 = 1111111111111111110

import java.util.Scanner;
import java.math.BigInteger;

public class Main {
    public static void main(String[] args) {
        BigInteger a,b,c;
        int n;
        Scanner cin = new Scanner(System.in);
        n = cin.nextInt();
        for(int i=1;i<=n;i++)
        {
        a = cin.nextBigInteger();
        b = cin.nextBigInteger();
        c = a.add(b);
        System.out.println("Case " + i + ":");
        System.out.println(a + " + " + b + " = " + c);
        if(i!=n)
            System.out.println();
        }
    }
}