这段c语言里面的sum是干什么的?
#include<stdio.h>#define M 4
void main()
{
int c[M] = {0};
int d[M][3] = { {1,5,7},(3,2,10},{6,7,9},{4,3,7}};
int i,j,sum=0;
for(i=0;i<M;i++){
for(j=0;j<3;j++)c[i] +=d[i][j];
sum+=c[i];
}
for (i=0;i<M;i++)printf("%d",c[i]);
printf("%d\n",sum);
}
