POJ 1631 Bridging signals

#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <string>
#include <algorithm>
using namespace std;

const int MAXN = 40100;
const int INF = 0x3f3f3f3f;

int A[MAXN];
int S[MAXN], d[MAXN];
int n;

void init()
{
	for(int i = 1; i <= n; i++) S[i] = INF;
	S[0] = -INF;
	d[0] = 0;
}

int BSearch(int x, int y, int q)
{
	while(x <= y)
	{
		int mid = x+(y-x)/2;
		if(S[mid] >= q) y = mid-1;
		else x = mid+1;
	}
	return x;
}

void dp()
{
	init();
	int ans = 0;
	for(int i = 1; i <= n; i++)
	{
		int x = 0, y = i;
		int pos = BSearch(x, y, A[i]);
		d[i] = pos;
		S[d[i]] = min(S[d[i]], A[i]);
		ans = max(ans, d[i]);
	}
	printf("%d\n", ans);
}

void read_case()
{
	scanf("%d", &n);
	for(int i = 1; i <= n; i++) scanf("%d", &A[i]);
}

void solve()
{
	read_case();
	dp();
}

int main()
{
	int T;
	scanf("%d", &T);
	while(T--)
	{
		solve();
	}
	return 0;
}