hdu 1950 Bridging signals【LIS nlogn】

题目链接：​​http://acm.hdu.edu.cn/showproblem.php?pid=1950​​

题意：LIS nlogn算法

代码：

#include <iostream>
#include <stdio.h>
#include <string>
#include <string.h>
#include <cmath>
#include <queue>
#include <vector>
#include <map>
#include <set>

using namespace std;

int ans[40010];
int a[40010];
int n;

int main()
{
    int T;
    scanf("%d",&T);
    while (T--)
    {
        memset(a,0,sizeof(a));
        memset(ans,0,sizeof(ans));
        scanf("%d",&n);
        for(int i=1;i<=n;i++)
            scanf("%d",&a[i]);
        ans [1] = a[1];
        int len = 1;

        for(int i=2;i<=n;i++)
        {
            if (a[i] > ans[len])
                ans[++len] = a[i];
            else
            {
                int left = 1,right = len;
                while (left <= right)
                {
                    int mid = (left + right)/2;
                    if (a[i] >= ans[mid]) left = mid + 1;
                    else right = mid - 1;
                }
                ans [left] = a[i];
            }
        }
        printf("%d\n",len);
    }
    return 0;
}