大数相加 C++版+java版

A + B Problem II

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 468200    Accepted Submission(s): 90552

 

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.

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Sample Input

2 1 2 112233445566778899 998877665544332211

Sample Output

Case 1: 1 + 2 = 3 Case 2: 112233445566778899 + 998877665544332211 = 1111111111111111110

Author

Ignatius.L

要注意格式啊，每两组测试用例之间有一空行，也就是说最后一组例子没空行。

自己写的：

很容易理解，模拟两个数相加

#include<iostream>
#include<cstring>
#include<cstdio>
using namespace std;
#define range 1005
int m=1;
void add(char a[],char b[],char c[])
{
	int i,j,k=0,current,carry=0,len;
	len=strlen(a)>strlen(b)?strlen(a):strlen(b);
	len+=3;
	char res[range];
	char x,y;
	i=strlen(a)-1;
	j=strlen(b)-1;
	while(i>=0||j>=0)
	{
		if(i<0)
		x='0';
		else
		x=a[i];
		if(j<0)
		y='0';
		else
		y=b[j];
		current=x-'0'+y-'0';
		if(carry)
		current+=1;
		if(current>9)
		{
			current%=10;
			carry=1;
		}
		else carry=0;   //这忘了一次，哇了两次 
		res[k++]=current+'0';
		i--;
		j--;
	}
	if(carry)
	res[k++]='1';
	res[k]='\0';
	
	for(i=k-1,j=0;i>=0;i--,j++)
	c[j]=res[i];
	c[j]='\0';
	return ;
}
int main()
{
	char a[range],b[range],c[range];
	int n;
	cin>>n;
	while(n--)
	{
		cin>>a>>b;
		add(a,b,c);
		
		cout<<"Case "<<m<<":"<<endl;
		cout<<a<<" + "<<b<<" = "<<c<<endl;
		if(n!=0)
		cout<<endl;
		m++;
	}
	return 0;
}

java版的：

开挂吧

package 大数;

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

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner in=new Scanner(System.in);
		int n=in.nextInt();
		int m=1;
		while(n>0)
		{
			BigDecimal a=in.nextBigDecimal();
			BigDecimal b=in.nextBigDecimal();
			System.out.println("Case "+m+":");
			System.out.println(a+" + "+b+" = "+a.add(b));
			if(n!=1)
				System.out.println();
			
			n--;
			m++;
		}

	}

}