lg3146[简单区间DP]

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链接:lg3146[简单区间DP]

题解

  • 简单区间DP,dp[i][j]表示i-j所取得的最大的值
  • dp[i][j]=max(dp[i][j],dp[i][k]+1) 当dp[i][k]==dp[k+1][j]的时候才可以转移
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#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cmath>
#include<cstring>
#include<map>
#include<algorithm>
#define rint register int
#define rep(i,x,y) for(rint i=x;i<=y;++i)
#define repd(i,x,y) for(rint i=x;i>=y;--i)
#define lowbit(x) (x&(-x))
#define ll long long
using namespace std;
const int N=1e3;
int dp[N][N],n,ans;
template <typename T>inline void read(T &x){
	x=0;char c;int sign=1;
	do{c=getchar();if(c=='-')sign=-1;}while(c<'0'||c>'9');
	do{x=x*10+c-'0'; c=getchar();}while(c>='0'&&c<='9');
	x*=sign;
}
int main(){
	read(n);
	rep(i,1,n){read(dp[i][i]),ans=max(ans,dp[i][i]);}
	repd(i,n-1,1)rep(j,i+1,n){
		rep(k,i,j-1)if(dp[i][k]==dp[k+1][j])dp[i][j]=max(dp[i][j],dp[i][k]+1);
		ans=max(ans,dp[i][j]);
	}
	cout<<ans<<endl;
	return 0;
}