luogu3146 [USACO16OPEN]248

细节被坑惨

#include<bits/stdc++.h>
using namespace std;
const int maxn=1e6+5;
const int INF=1e9+7;
int n,ans,dp[305][305];
template <class t>void red(t &x)
{
    x=0;
    int w=1;
    char ch=getchar();
    while(ch<'0'||ch>'9')
    {
        if(ch=='-')
            w=-1;
        ch=getchar();
    }
    while(ch>='0'&&ch<='9')
    {
        x=(x<<3)+(x<<1)+ch-'0';
        ch=getchar();
    }
    x*=w;
}
void input()
{
    freopen("input.txt","r",stdin);
}
void read()
{
    red(n);
    for(int i=1;i<=n;++i)
        red(dp[i][i]); 
}
void work()
{
    for(int i=1;i<=n;++i)
        for(int j=1;j+i<=n+1;++j)
        {
            int e=i+j-1;
            for(int k=j;k<e;++k)
                if(dp[j][k]==dp[k+1][e]) 
                    dp[j][e]=max(dp[j][e],dp[j][k]+1);
                ans=max(ans,dp[j][e]);
            //    else
            //        dp[j][e]=max(dp[j][e],max(dp[j][k],dp[k+1][e]));
        }
    printf("%d",ans);
}
int main()
{
    //input();
    read();
    work();
    return 0;
}