Q10370: Above Average

Problem D: Above Average

It is said that 90% of frosh expect to be above average in their class. You are to provide a reality check.

The first line of standard input contains an integer C, the number of test cases. C data sets follow. Each data set begins with an integer, N, the number of people in the class (1 <= N <= 1000). N integers follow, separated by spaces or newlines, each giving the final grade (an integer between 0 and 100) of a student in the class. For each case you are to output a line giving the percentage of students whose grade is above average, rounded to 3 decimal places.

Sample Input

5
5 50 50 70 80 100
7 100 95 90 80 70 60 50
3 70 90 80
3 70 90 81
9 100 99 98 97 96 95 94 93 91

Output for Sample Input

40.000%
57.143%
33.333%
66.667%
55.556%

#include<stdio.h>
main()
{
float c,bi,n,a[1000],av,m=0;
int i;
scanf("%f",&c);
while(c--)
{
scanf("%f",&n);
for(i=0;i<n;i++)
{
scanf("%f",&a[i]);
av+=a[i];
}
av=av/n;
for(i=0;i<n;i++)
if(a[i]>av)
m+=1;
bi=m/n;
bi=bi*100;
printf("%0.3f",bi);
printf("%%\n");
}
}

 

这题得先求出成绩的平均值，然后再用这个平均值与成绩一个一个比较，算出有多少个成绩超过平均成绩，接着就能算出多少百分比了。