POJ 2533

最长上升子序列裸题
在网上看到有两种方法...一种复杂度O(N^2)，一种O(NlogN)。orz

O(N^2)：

#include<cstdio>
#define N 1001
int main()
{
    int n,ans;
    int a[N],d[N];

    while(~scanf("%d",&n)){
    for(int i=; i<=n; i++)
        scanf("%d",&a[i]);

    ans=;
    for(int i=; i<=n; i++)
    {
        d[i]=;
        for(int j=; j<=i-; j++)
        {
            if(a[i]>a[j] && d[i]<d[j]+)
                d[i]=d[j]+;
        }
        if(d[i]>ans)
            ans=d[i];
    }
    printf("%d\n",ans);
    }
    return ;
}

O(NlogN)：

 #include <cstdio>
    using namespace std;  

    const int maxn =  + ;
    int n, num[maxn], LIS[maxn];  

    int binary_search(int start, int end, int target)
    {
        while (end > start) {
            int mid = (end + start) / ;
            if (target > LIS[mid])
                start = mid + ;
            else
                end = mid;
        }
        return start;
    }  

    int lis()
    {
        LIS[] = num[];
        int maxl = ;
        for (int i = ; i <= n; ++i) {
            if (num[i] > LIS[maxl])
                LIS[++maxl] = num[i];
            else {
                int pos = binary_search(, maxl, num[i]);
                LIS[pos] = num[i];
            }
        }
        return maxl;
    }  

    int main()
    {
        scanf("%d", &n);
        for (int i = ; i <= n; ++i)
            scanf("%d", &num[i]);
        printf("%d\n", lis());
    }