#689139 (C++14) No.1646 Avoid Palindrome

• 問題: No.1646 Avoid Palindrome
• ユーザー: inksamurai
• 提出日時: 2021-08-13 22:05:35
• 言語: C++14 (gcc 13.3.0 + boost 1.87.0)
• 結果: AC
• 実行時間: 2,159 ms / 3,000 ms
• コード長: 2,607 bytes
• コンパイル時間: 1,339 ms
• コンパイル使用メモリ: 110,104 KB
• 実行使用メモリ: 415,488 KB
• 最終ジャッジ日時: 2024-11-08 15:20:40
• 合計ジャッジ時間: 46,463 ms
• ジャッジサーバーID （参考情報）: judge1 / judge4

ファイルパターン	結果
sample	AC * 4
other	AC * 40

ソースコード

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#include <cmath>
#include <deque>
#include <algorithm>
#include <iterator>
#include <list>
#include <tuple>
#include <map>
#include <unordered_map>
#include <queue>
#include <set>
#include <unordered_set>
#include <stack>
#include <string>
#include <vector>
#include <fstream>
#include <iostream>
#include <functional>
#include <numeric>
#include <iomanip> 
#include <stdio.h>
#include <assert.h>
#include <cstring>
//eolibraries
#define lnf 3999999999999999999
#define inf 999999999
#define fi first
#define se second
#define pb push_back
#define ll long long
#define ld long double
#define all(c) (c).begin(),(c).end()
#define sz(c) (int)(c).size()
#define make_unique(a) sort(all(a)),a.erase(unique(all(a)),a.end())
#define pii pair <int,int>
#define rep(i,n) for(int i = 0 ; i < n ; i++) 
#define drep(i,n) for(int i = n-1 ; i >= 0 ; i--)
#define crep(i,x,n) for(int i = x ; i < n ; i++)
#define vi vector <int> 
#define vec(...) vector<__VA_ARGS__>
#define _3yHSMG9 ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0)
//eodefine
using namespace std;
const int mxn=12000;
//snuke's modular int
template <ll mod>
struct modularint{
    ll x;
    modularint(ll x=0):x(x%mod){}
    modularint& operator+=(const modularint a){
        if ((x += a.x) >= mod) x -= mod;
        return *this;
    }
    modularint& operator-=(const modularint a){
        if ((x += mod-a.x) >= mod) x -= mod;
        return *this;
    }
    modularint& operator*=(const modularint a){
        (x *= a.x) %= mod;
        return *this;
    }
    modularint operator+(const modularint a)const{
        modularint res(*this);
        return res+=a;
    }
    modularint operator-(const modularint a)const{
        modularint res(*this);
        return res-=a;
    }
    modularint operator*(const modularint a)const{
        modularint res(*this);
        return res*=a;
    }
    modularint pow(ll n)const{
        modularint res=1,x(*this);
        while(n){
            if(n&1)res*=x;
            x*=x;
            n>>=1;
        }
        return res;
    }
    modularint inv()const{
        return pow(mod-2);
    }
};
using mint=modularint<998244353>;
int main(){
_3yHSMG9;
    int n;
    cin>>n;
    string s;
    cin>>s;
    vec(vec(vec(mint))) dp(n+2,vec(vec(mint))(30,vec(mint)(30)));
    dp[0][0][0]=1;
    rep(i,n){
        rep(x,27){
            rep(y,27){
                // if(x==y) continue;
                if(dp[i][x][y].x==0) continue;
                if(s[i]=='?'){
                    crep(now,1,27){
                        if(x==now or y==now) continue;
                        dp[i+1][y][now]+=dp[i][x][y];
                    }
                }else{
                    int now=s[i]-'a'+1;
                    // if(i==0) cout<<now<<"\n";
                    if(x==now or y==now) continue;
                    dp[i+1][y][now]+=dp[i][x][y];
                }
            }
        }
    }
    mint ans=0;
    rep(x,27){
        rep(y,27){
            ans+=dp[n][x][y];
        }
    }
    // cout<<dp[1][0][1].x<<"\n";
    cout<<ans.x<<"\n";
//  
    return 0;
}
 
 
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