hdoj 1202 the calculation of GPA（水题）

思路：直接给代码了

代码如下：

#include <iostream>  #include <stdio.h>#include <stdlib.h>#include <string.h>#include <math.h>#include <algorithm>#include <vector>using namespace std;int main(){int n;double s,p;double sum1,sum2;while(scanf("%d",&n)!=EOF){sum1=sum2=0.0;while(n--){scanf("%lf%lf",&s,&p);if((int)p+1==0)continue;sum1+=s;if(p>=90)sum2+=4*s;else if(p>=80)sum2+=3*s;else if(p>=70)sum2+=2*s;else if(p>=60)sum2+=s; }if(sum1!=0)printf("%.2lf\n",sum2/sum1);else printf("-1\n");}                                    return 0;        }