输入10个学生5门课成绩，分别用函数实现下列功能

#include<stdio.h>
#include<string.h>
#define N 10
float a_stu
;
int average1(int str1[][5],int m,int n);
int average2(int str1[][5],int m,int n);
int average3(int str1[][5],int m,int n);
int average4(int str1[][5],int m,int n);
int main()
{
int str[10][5]={{87,88,92,67,78},{88,86,87,98,90},{76,75,65,65,78},{67,87,60,90,67},
{77,78,85,64,56},{76,89,94,65,76},{78,75,64,67,77},{77,76,56,87,85},{84,67,78,76,89},
{86,75,64,69,90}};
int i,j;
printf("每个学生的平均成绩\n");
average1(str,10,5);
printf("每门课的平均成绩\n");
average2(str,10,5);
average3(str,10,5);
printf("某个学生的平均成绩的偏差\n");
average4(str,10,5);
return 0;

}
int average1(int str1[][5],int m,int n)//单个学生的平均成绩
{
int i,j;

float average1;
for(i=0;i<m;i++)
{
float sum=0;
for(j=0;j<n;j++)
{
sum+=str1[i][j];

}
a_stu[i]=sum/n;
printf("%.2f\n",a_stu[i]);
}

}

int average2(int str1[][5],int m,int n)//单门课的平均成绩
{
int i,j;

float average2;
for(j=0;j<n;j++)
{
float sum=0;
for(i=0;i<m;i++)
{
sum+=str1[i][j];

}
average2=sum/m;
printf("%.2f\n",average2);
}

}
int average3(int str1[][5],int m,int n)
{
int max=str1[0][0];
int p,k,i,j;
for(i=0;i<10;i++)
{
for(j=0;j<5;j++)
if(str1[i][j]>max)
{
max=str1[i][j];
k=i+1;
p=j+1;
}

}
printf("最高分对应的学生和课程\n");
printf("max=%d,k=%d,p=%d\n",max,k,p);
}
int average4(int str1[][5],int m,int n)//某个学生的平均偏差
{
int i;
float sum1=0,sum2=0;
float average4;
for(i=0;i<m;i++)
{

sum1+=a_stu[i];
sum2+= a_stu[i]*a_stu[i];
average4=sum2/m-(sum1/m)*(sum1/m);

}
printf("%.2f\n",average4);

}