C语言第六章课后题3：输入全部学生个门成绩，求每门课平均成绩

int c[3][4];
int i,j;
for (i=0; i<3; i++)
for (j=0; j<4; j++)
scanf("%d", &c[i][j]);

int avg1, avg2, avg3, avg4;
int sum=0;
for (i=0; i<3; i++)
sum=c[i][0]+sum;
avg1=sum/4;

sum=0;
for (i=0; i<3; i++)
sum=c[i][1]+sum;
avg2=sum/4;

sum=0;
for (i=0; i<3; i++)
sum=c[i][2]+sum;
avg3=sum/4;

sum=0;
for (i=0; i<3; i++)
sum=c[i][3]+sum;
avg4=sum/4;

printf("每门课的平均成绩分别为%d %d %d %d", avg1, avg2, avg3, avg4);