【模板】最长递增子序列

#include <stdio.h>  
#include <algorithm>  
#include <string.h>  
using namespace std;  
  
int a[1005],dp[1005],n;  
  
int LIS()  
{  
    int i,j,ans,m;  
    dp[1] = 1;  
    ans = 1;  
    for(i = 2;i<=n;i++)  
    {  
        m = 0;  
        for(j = 1;j<i;j++)  
        {  
            if(dp[j]>m && a[j]<a[i])  
            m = dp[j];  
        }  
        dp[i] = m+1;  
        if(dp[i]>ans)  
        ans = dp[i];  
    }  
    return ans;  
}  

优化：

#include <stdio.h>  
#include <string.h>  
#include <algorithm>  
using namespace std;  
  
int a[40005],dp[40005],n;  
  
int bin(int size,int k)  
{  
    int l = 1,r = size;  
    while(l<=r)  
    {  
        int mid = (l+r)/2;  
        if(k>dp[mid])  
            l = mid+1;  
        else  
            r = mid-1;  
    }  
    return l;  
}  
  
int LIS()  
{  
    int i,j,ans=1;  
    dp[1] = a[1];  
    for(i = 2; i<=n; i++)  
    {  
        if(a[i]<=dp[1])  
            j = 1;  
        else if(a[i]>dp[ans])  
            j = ++ans;  
        else  
            j = bin(ans,a[i]);  
        dp[j] = a[i];  
    }  
    return ans;  
}