1002 A+B for Polynomials (25 分)

#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;
const int maxN = 1111;
double F[maxN] = {};
int main(int argc, char *argv[]) {
    int k, key, count = 0;          
    double value;
    
    scanf("%d", &k);
    for(int i=0; i<k; i++) {
        scanf("%d %lf", &key, &value);
        F[key] += value;
    }
    
    scanf("%d", &k);
    for(int i=0; i<k; i++) {
        scanf("%d %lf", &key, &value);
        F[key] += value;
    }
    
    for(int i=0; i<maxN; i++) {
        if(F[i] != 0) count++;
    }
    
    printf("%d", count);
    for(int i=maxN-1; i>=0; i--) {
        if(F[i] != 0) printf(" %d %.1lf", i, F[i]);
    }
}