LCIS HDOJ 4512 吉哥系列故事——完美队形I

 

题目传送门

题意：中文题面

分析：LCIS应用：设置b[]为a[]的反转，然后LCIS，若相等的是自己本身，则+1， 否则+2

 

代码：

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
using namespace std;

const int MAXN = 2e2 + 10;
const int INF = 0x3f3f3f3f;
int a[MAXN], b[MAXN];
int dp[MAXN][MAXN];
int n;

int LCIS(void)
{
    int k = 0;    int ans = 0;
    for (int i=1; i<=n; ++i)
    {
        k = 0;    
        for (int j=1; j<=n-i+1; ++j)
        {
            dp[i][j] = dp[i-1][j];
            if (a[i] == b[j])
            {
                if (j != n - i + 1)
                {
                    if (dp[i][j] < dp[i][k] + 2)
                        dp[i][j] = dp[i][k] + 2;
                }
                else
                {
                    if (dp[i][j] < dp[i][k] + 1)
                        dp[i][j] = dp[i][k] + 1;
                }
            }
            else if (a[i] > b[j])
                if (dp[i][j] > dp[i][k])    k = j;

            if (ans < dp[i][j])    ans = dp[i][j];
        }
    }

    return ans;
}

int main(void)        //HDOJ 4512 吉哥系列故事——完美队形I
{
    //freopen ("HDOJ_4512.in", "r", stdin);

    int t;
    scanf ("%d", &t);
    while (t--)
    {
        scanf ("%d", &n);

        for (int i=1; i<=n; ++i)    scanf ("%d", &a[i]);
        for (int i=1; i<=n; ++i)    b[n-i+1] = a[i];
        memset (dp, 0, sizeof (dp));

        printf ("%d\n", LCIS ());
    }

    return 0;    
}