题解 | #学分绩点#

#include<cstdio>
#include<vector>
using namespace std;
double run(int n){
	if (n >= 90){
		return 4.0;
	}
	else if (n >= 85 && n <= 89){
		return 3.7;
	}
	else if (n >= 82 && n <= 84){
		return 3.3;
	}
	else if (n >= 78 && n <= 81){
		return 3.0;
	}
	else if (n >= 75 && n <= 77){
		return 2.7;
	}
	else if (n >= 72 && n <= 74){
		return 2.3;
	}
	else if (n >= 68 && n <= 71){
		return 2.0;
	}
	else if (n >= 64 && n <= 67){
		return 1.5;
	}
	else if (n >= 60 && n <= 63){
		return 1.0;
	}
	else {
		return 0;
	}
}
int main(){
	int n;
	while (scanf("%d", &n) != EOF){
		vector<int>vec1;
		vector<int>vec2;
		int sum = 0;
		for (int i = 0; i < n; i++){
			int q;
			scanf("%d", &q);
			vec1.push_back(q);
			sum = sum + q;
		}
		for (int i = 0; i < n; i++){
			int q;
			scanf("%d", &q);
			vec2.push_back(q);
		}
		float GPA=0;
		for (int i = 0; i < n; i++){
			GPA = vec1[i] * run(vec2[i])+GPA;
		}
		GPA = GPA / sum;
		printf("%.2f", GPA);
	}
}