poj3903

最长上升子序列

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#include <iostream>

#include <cstdlib>

#include <cstdio>

#include <cstring>

#include <algorithm>

using namespace std;



#define maxn 100005



int n;

int top;

int stk[maxn];



int binarysearch(int l, int r, int a)

{

    if (l > r)

        return l;

    if (a > stk[r])

        return r + 1;

    while (l < r)

    {

        int mid = (l + r) / 2;

        if (stk[mid] < a)

            l = mid + 1;

        else

            r = mid;

    }

    return l;

}



int main()

{

    //freopen("t.txt", "r", stdin);

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

    {

        top = 0;

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

        {

            int a;

            scanf("%d", &a);

            int index = binarysearch(0, top - 1, a);

            stk[index] = a;

            top = max(top, index + 1);

        }

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

    }

    return 0;

}