读入n个（整型）成绩，输出平均成绩（实型），最好成绩，最差成绩，以及转换从优良中差及格。

#include<stdio.h>
int main()
{
  int i,j,n,t,a[100];
  int sum = 0,ping,you=0,liang=0,zhong=0,cha=0;
  printf("请输入n位同学的成绩：\n");
  scanf("%d", &n);
  for (i = 0; i < n; i++)
  {
    scanf("%d", &a[i]);
    sum = sum + a[i];
  }
  ping = sum/n;
  printf("这%d位同学的平均成绩为%d\n",n,ping);
  //气泡法排序数组
  for(j=0;j<n-1;j++)
    for(i=0;i<n-1-j;i++)
      if (a[i] > a[i + 1])
      {
        t = a[i];
        a[i] = a[i + 1];
        a[i + 1] = t;
      }
  printf("这%d位同学的最高分为%d\n", n, a[n-1]);
  printf("这%d位同学的最低分为%d\n", n, a[0]);
  for (i = 0; a[i] != '\0'; i++)
  {
    if (a[i] >= 90 && a[i] <= 100)
      printf("%d优秀\n",a[i]);
    else if (a[i] >= 75 && a[i] < 90)
      printf("%d优良\n",a[i]);
    else if (a[i] >= 60 && a[i] < 75)
      printf("%d中等\n",a[i]);
    else if (a[i] >= 0 && a[i] < 60)
      printf("%d差\n",a[i]);
  }
  return 0;
}