poj2533

最长递增子序列

#include <iostream>

#include <cstdlib>

#include <cstdio>

#include <cstring>

using namespace std;



#define maxn 40004



int n;

int f[maxn];

int d[maxn];

int m;



void input()

{

    scanf("%d", &n);

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

        scanf("%d", &f[i]);

}



int binarysearch(int a)

{

    int l = 0;

    int r = m;

    while (l < r)

    {

        int mid = (l + r) / 2;

        if (d[mid] < a)

            l = mid + 1;

        else

            r = mid;

    }

    if (l >= m)

        m++;

    return l;

}



int work()

{

    m = 0;

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

        d[binarysearch(f[i])] = f[i];

    return m;

}



int main()

{

    input();

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

    return 0;

}

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