> #include<iostream>
> #include<algorithm>
> using namespace std;
> 
> int main(void)
> {
> 	int t;
> 	scanf("%d",&t);
> 	while(t--)
> 	{
> 		int a,b;
> 		char s1[13],s2[13];
> 		scanf("%d%d",&a,&b);
> 		sprintf(s1,"%d",a);
> 		sprintf(s2,"%d",b);
> 		reverse(s1,s1+strlen(s1));
> 		reverse(s2,s2+strlen(s2));
> 		sscanf(s1,"%d",&a);
> 		sscanf(s2,"%d",&b);
> 		sprintf(s1,"%d",a+b);
> 		reverse(s1,s1+strlen(s1));
> 		sscanf(s1,"%d",&a);
> 		printf("%d\n",a);
> 	}
> 	return 0;
> }

要是大整数的话,这样就不行了