Codeforces 607 D Zuma

[code]#include<iostream>
#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<queue>
#include<math.h>
#include<stdlib.h>
#include<vector>
#include<map>
#include<string>
using namespace std;
#define ll long long
#define For(i,n) for(int i=1;i<=n;i++)
#define Dor(i,n) for(int i=n;i>=1;i--)
#define s(n) scanf("%d",&n)
#define p(n) printf("%d\n",n)
#define ms(n) memset(n,0,sizeof(n))
#define lson l , m , rt << 1
#define rson m + 1 , r , rt << 1 | 1
const double eps=1e-8;
const int inf=0x3f3f3f3f;
const int maxn=1e5+10;
int  n, a[505];
int dp[505][505];
int dfs(int l,int r)
{
    int &ans=dp[l][r];
    if(ans!=inf) return ans;
    if(r==l) return ans=1;
    if(r-l==1)
    {
        if(a[l]==a[r]) return ans=1;
        else return ans=2;
    }
    //it should not return directly because the current solution may not be most perfect
    if(a[l]==a[r])  ans=dfs(l+1,r-1);
    for(int i=l;i<r;i++)
    {
        ans=min(ans,dfs(l,i)+dfs(i+1,r));
    }
    return ans;
}
int main()
{
    cin>>n;
    for(int i=1;i<=n;i++)
      for(int j=1;j<=n;j++)
         dp[i][j]=inf;
    for(int i=1;i<=n;i++)
    {
        s(a[i]);
    }
    printf("%d\n",dfs(1,n));
    return 0;
}