#include <iostream>
#include <string>
using namespace std;


string strplus(string left, string right)
{
	
	int large = left.size()>right.size() ? left.size() : right.size();
	int small = left.size()<right.size() ? left.size() : right.size();
	int flag = 0;
	if(left.size()>right.size())
		flag=1;
	string ret=""; int carry=0;
	for(int i=0; i<small; i++)
	{
		int  l=left[i]-'0';
		int  r=right[i]-'0';
		int sum = l+r+carry;
		if(sum>=10)
			carry=1;
		else carry = 0;
		int reted = sum % 10;
		char c = '0'+reted;
		ret += c;
	}
	for(i=small; i<large; i++)
	{
		if(flag)
		{
			int l= left[i]-'0';
			int sum = l+carry;
			if(sum>=10)
				carry = 1;
			else
				carry = 0;
			char c = '0' + sum%10;
			ret += c;
		}
		else
		{
			int l= right[i]-'0';
			int sum = l+carry;
			if(sum>=10)
				carry = 1;
			else
				carry = 0;
			char c = '0' + sum%10;
			ret += c;
		}
	}
	if(carry == 1)
	{
		char c = '1';
		ret += c;
	}
	int len=0;
	for(i=0; i<ret.size();i++)
	{
		if(ret[i]=='0')
		{
			len++;
		}
		else
		{
			break;
		}
	}
	ret.erase(0,len);

	return ret;
}
int main()
{
	int cases;
	cin>>cases;
	string left, right;
	while(cases--)
	{
		cin>>left>>right;	
		string ret = strplus(left,right);
		cout<<ret<<endl; 
	}
	return 0;
}


和 

#include <stdio.h>
#include <string.h>
int reverse(int n)
{
	char str[100];
	int i = 0;
	while(n)
	{
		str[i++] = n % 10 + '0';
		n /=  10;
	}
	str[i] = 0;
	sscanf(str, "%d", &n);
	return n;
}
int main()
{
	int T, a, b;
	scanf("%d", &T);
	while(T--)
	{
		scanf("%d%d", &a, &b);
		printf("%d\n", reverse(reverse(a) + reverse(b)));
	}
	return 0;
}


比如 102 002
一个输出104， 一个输出302
我用java将这2个理解的都写的，但是都是wa，晕

• 用c又写了一遍，找到为什么wa了 (149) bottles 2009-03-16 19:42:11
  • Re:用c又写了一遍，找到为什么wa了 (169) sherlockjk 2009-07-30 09:52:50
    • 真的，一定要注意，我就是少了一个long，贡献了2个WA (28) sherlockjk 2009-07-30 09:53:48
    • 感谢楼主，一开始用的_int64 原来不好使 后改用的long long (0) is5land 2010-03-06 22:29:41