{POJ}{3903}{Stock Exchange}{nlogn 最长上升子序列}

题意：求最长上升子序列，n=100000

思路：O(N^2)铁定超时啊。。。。利用贪心的思想去找答案。利用栈，每次输入数据检查栈，二分查找替换掉最小比他大的数据，这样得到的栈就是更优的。这个题目确实不错，思路很好

#include <iostream>

#include <string>

#include <cstring>

#include <cstdio>

#include <algorithm>

#include <memory>

#include <cmath>

#include <bitset>

#include <queue>

#include <vector>

#include <stack>

using namespace std;

 

 

#define CLR(x,y) memset(x,y,sizeof(x))

#define MIN(m,v) (m)<(v)?(m):(v)

#define MAX(m,v) (m)>(v)?(m):(v)

#define ABS(x) ((x)>0?(x):-(x))

#define rep(i,x,y) for(i=x;i<y;++i)





const int MAXN = 110000;



int n,m;

int len;

int val;

int s[MAXN];



int BF(int cur)

{

	int low,high,mid;

	int pre;



	low = 0;

	high = len-1;

	while(low <= high)

	{

		mid = (low+high)>>1;

		if(s[mid]<cur){

			low = mid+1;

		}

		else if(s[mid]>cur){

			high = mid-1;

		}

		else 

			return mid;

	}

	return low;

}

void Solve()

{

	while(scanf("%d",&n)!=EOF)

	{

		len = 0;

		for(int i = 0 ; i < n; ++i)

		{

			scanf("%d",&val);

			if(len == 0 || s[len-1] < val){

				s[len] = val;

				++len;

			}

			else

			{

				int f = BF(val);

				s[f] = val;

			}

		}



		printf("%d\n",len);

	}

}



int main()

{

	Solve();



	return 0;

}