PAT a 1009题解

#include 

struct Poly{
	int exp;
	double cof;
} poly[1001];

double ans[2001];

int main(){
	int n, m, number = 0;
	scanf("%d", &n);
	for(int i = 0; i < n; i++){
		scanf("%d %lf", &poly[i].exp, &poly[i].cof);
	}
	scanf("%d", &m);
	for(int i = 0; i < m; i++){
		int exp;
		double cof;
		scanf("%d %lf", &exp, &cof);
		for(int j = 0; j < n; j++){
			ans[exp + poly[j].exp] += (cof * poly[j].cof);
		}	
	}
	for(int i = 0; i <= 2000; i++){
		if(ans[i] != 0.0){
			number++;
		}
	}
	printf("%d", number);
	for(int i = 2000; i >= 0; i--){
		if(ans[i] != 0.0){
			printf(" %d %.1f", i, ans[i]);
		}
	} 
	return 0;
}