[ACM]HDU Problem 1002 + Java

import java.util.Scanner;
import java.math.BigDecimal;

public class Main {
	public static void main(String args[]){
		Scanner input = new Scanner(System.in);
		
		int T = input.nextInt();
		
		for(int i = 1; i <= T; i++){
			BigDecimal a = input.nextBigDecimal();
			BigDecimal b = input.nextBigDecimal();
			BigDecimal sum = a.add(b);
			System.out.println("Case " + i + ":");
			System.out.print(a + " + " + b + " = " + sum);
			if(i != T){
				System.out.println();
			}
			System.out.println();
		}
	}
}

　　

此外我还按照手动演算进位的方法写了一种，有点绕，但是也AC了，仅供参考。

import java.util.Scanner;

public class Main {
	public static void main(String args[]){
		Scanner input = new Scanner(System.in);
		
		int T = input.nextInt();
		int cnt = T;
		while(T != 0){
			int sum[] = new int[1001];
			sum[0] = 0;

			String sa = input.next();
			String sb = input.next();
			int la = sa.length();
			int lb = sb.length();
			
			int d = 0;
			int length = la > lb ? (la+1) : (lb+1);
			
			for(int i = length-1; i > 0; i--){
				int sa1, sb1;
				if(la > 0){ 
					sa1 = sa.charAt(la-1) - '0';
				} else{ 
					sa1 = 0; 
				}
				if(lb > 0){ 
					sb1 = sb.charAt(lb-1) - '0';
				} else{ 
					sb1 = 0;
				}
				sum[i] = (sa1 + sb1 + d) % 10;
				d= (sa1 + sb1 + d) / 10;
				la--;
				lb--;
			}
			sum[0] = d;
			
			StringBuffer str = new StringBuffer();
			if(sum[0] != 0) 
				//System.out.print(sum[0]);
				str.append(sum[0]);
			for(int i = 1; i < length; i++){
				//System.out.print(sum[i]);
				str.append(sum[i]);
			}
			
			System.out.println("Case " + (cnt-T+1) + ":");
			System.out.print(sa + " + " + sb + " = " + str);
		
			if(T != 1){
				System.out.println();
			}
			System.out.println();
			T--;
		}
		input.close();
	}
}