C语言-输出矩阵对角线之和

#include<stdio.h>
#include<stdlib.h>
int main() {
	int a[3][3]={1,3,5,7,9,11,13,15,17},sum1=0,sum2=0,i,j;
	for(i=0; i<3; i++)
		for(j=0; j<3; j++)
			if(i==j)//If i is j (the first diagonal line)//
				sum1=sum1+a[i][j];
	for(i=0; i<3; i++)
		for(j=2; j>=0; j--)//The second diagonal line//
			if((j+i)==2)
				sum2=sum2+a[i][j];
	printf("sum1=%d sum2=%d\n",sum1,sum2);//output format//
	system("pause");
	return 0;

}