poj 1631 Bridging signals

#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
int n,sor[500010],num[500010];
void task()
{
	int i,M=0;
	sor[0]=num[0];
	for(i=1;i<n;i++)
	{
		int low=0,high=M;
		while(low<=high)
		{
			int mid=(low+high)/2;
			if(sor[mid]<num[i]) low=mid+1;
			else high=mid-1;
		}
		if(low>M) M++;
		sor[low]=num[i];
	}
	printf("%d\n",M+1);
}
int main()
{
	int t,m,i,j,k;
	while(scanf("%d",&t)!=EOF)
	{
		while(t--)
		{
			scanf("%d",&n);
		  for(i=0;i<n;i++)
		  {
			scanf("%d",&num[i]);
		  }
		  task();
		}	
	}
	return 0;
}