int a[][3]={1,2,3,4,5,6,7}; 
	printf("sizeof(a)/sizeof(int)=%d\n",sizeof(a)/sizeof(int));
	int i,j;
	for(i=0;i<3;i++)
		for(j=0;j<3;j++)
	    printf("%d\n",a[i][j]);
		/*
		sizeof(a)/sizeof(int)=9
		1
		2
		3
		4
		5
		6
		7
		0
		0
		*/