以下程序的输出结果是()intmain(){inta[3][3]={1,2,3,4,5,6,7,8,9};intsum=0,i,j;for(i=0;i<3;i++)for(j=0;j<3;j++)if(i==j)sum=sum+a[i][j];printf(“sum=%d”,sum);}