平均数中位数众数

#include <stdio.h> 
#define  M   10 
#define  N   11 
int Mean(int answer[], int n); 
int Median(int answer[], int n); 
int Mode(int answer[], int n); 
void DataSort(int a[], int n); 
int main() 
{ 
    int  i, feedback[M]; 
    printf("Input the feedbacks of 10 students:\n"); 
    for (i = 0; i < M; i++) 
    { 
        scanf("%d", &feedback[i]); 
    } 
    printf("Mean value = %d\n", Mean(feedback, M)); 
    printf("Median value = %d\n", Median(feedback, M)); 
    printf("Mode value = %d\n", Mode(feedback, M)); 
    return 0; 
} 
/* 函数功能：若n>0则计算并返回n个数的平均数，否则返回-1 */
int Mean(int answer[], int n) 
{ 
    int i, sum = 0; 
    for (i = 0; i < n; i++) 
    { 
        sum += answer[i]; 
    } 
    return  n > 0 ? sum / n : -1; 
}