Question

main() { int i,t[][3]={9,8,7,6,5,4,3,2,1}; for(i=0;i<3;i++) printf("%d",t[2-i][i]);}结果是

Answer 1

3 5 7
实际上t[][3]=t[3][3]= {{9,8,7},{6,5,4},{3,2,1}}
再由循环
i=0,t[2][0]=3
i=1,t[1][1]=5
i=2,t[0][2]=7
i=3循环结束
即
t[2][0]=3
t[1][1]=5
t[0][2]=7

Answer 2

#define N 10
main()
{
int a[N]=;
int i,j,t;
printf("Before:\n");
for(i=0;i<=N-1;i++)
printf("%4d",a[i]);
printf("\n");
for (i=0,j=N-1;i<j;i++,j--)
{ t=a[i];
a[i]=a[j];
a[j]=t;
}
printf("After:\n");
for(i=0;i<=N-1;i++)
printf("%4d",a[i]);
printf("\n");
}

加个头包含文件，以及在数组定义后面少‘；’号

Answer 3

357

Answer 4

357

Answer 5

357