下面是求一个矩阵主、副对角线元素之和的程序,请填空将程序补充完整。#include
int main( ){int a[4][4]={{1, 2, 3, 6},{9, 6, 7, 8},{5, 9, 10,2}, {7, 2, 9,6}};int i,j,sum1=0,sum2=0;for(i=0;i<4;i++)for(j=0;j<4;j++){ ________________ sum1=sum1+a[i][j]; if(i+j==3) sum2=sum2+a[i][j];}printf("sum1=%d,sum2=%d\n",sum1,sum2); return 0;}