include<stdio.h>

include<stdlib.h>

int cmp ( const void *a, const void *b )
{
return *(int *)a - *(int *)b; //强制转换类型
}
int main()
{
int T,i,j,x,a[100005],sum;
scanf("%d",&T);
while(T--)
{

    j=1;
    scanf("%d",&x);
    for(i=0 ; i<x ; i++)
        scanf("%d",&a[i]);
    qsort(a,x,sizeof(a[0]),cmp);
    for(i=0,sum=x; i<x-1 ; i++)
    {
        if(a[i]==a[i+1])
            sum--;
    }
    printf("%d\n",sum);
}
return 0;

}
本题C语言解法,