codeforces 607B(區間ｄｐ)

題目鏈接：https://codeforc.es/problemset/problem/607/B

思路：模板題，枚舉一下斷點，區間左右端點相同更新一下就好

#include <cstdio>
#include <cstdlib>
#include <cassert>
#include <cstring>
#include <bitset>
#include <cmath>
#include <cctype>
#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <queue>
#include <map>
#include <set>
#include <sstream>
#include <iomanip>
using namespace std;
typedef long long ll;
typedef vector<long long> VI;
typedef unsigned long long ull;
const ll inff = 0x3f3f3f3f3f3f3f3f;
#define FOR(i,a,b) for(int i(a);i<=(b);++i)
#define FOL(i,a,b) for(int i(a);i>=(b);--i)
#define SZ(x) ((long long)(x).size())
#define REW(a,b) memset(a,b,sizeof(a))
#define inf int(0x3f3f3f3f)
#define si(a) scanf("%d",&a)
#define sl(a) scanf("%lld",&a)
#define sd(a) scanf("%lf",&a)
#define ss(a) scanf("%s",a)
#define mod ll(998244353)
#define pb push_back
#define eps 1e-6
#define lc d<<1
#define rc d<<1|1
#define Pll pair<ll,ll>
#define P pair<int,int>
#define pi acos(-1)
int n,a[508],dp[508][508];
int dfs(int l,int r)
{
    if(l>r) return 1;
    if(dp[l][r]) return dp[l][r];
    if(l==r) return dp[l][r]=1;
    int res=inf;
    if(a[l]==a[r]) res=min(res,dfs(l+1,r-1));
    for(int k=l;k<r;k++) res=min(res,dfs(l,k)+dfs(k+1,r));
    return dp[l][r]=res;
}
int main()
{
    cin.tie(0);
    cout.tie(0);
    cin>>n;
    FOR(i,1,n) si(a[i]);
    cout<<dfs(1,n)<<endl;
    return 0;
}