PAT甲级1002水题飘过

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

 double a[];

 int main(){
     int n1, n2;
     while(scanf("%d", &n1) != EOF){
         memset(a, , sizeof(a));
         for(int i = ; i <= n1; i++){
             int x;
             double y;
             scanf("%d%lf", &x, &y);
             a[x] += y;
         }
         scanf("%d", &n2);
         for(int i = ; i <= n2; i++){
             int x;
             double y;
             scanf("%d%lf", &x, &y);
             a[x] += y;
         }
         int cnt = ;
         for(int i = ; i <= ; i++){
             if(a[i] != ) cnt++;
         }
         printf("%d", cnt);
         for(int i = ; i >= ; i--){
             if(a[i] != ){
                 printf(" %d %.1lf", i, a[i]);
             }
         }
         printf("\n");
     }
     return ;
 }