Submission #75428230

---

Source Code Expand

#line 2 "/Users/blue_jam/ProconLibrary/misc/template.hpp"

#include <atcoder/all>
#include <bits/stdc++.h>

using namespace std;
using namespace atcoder;

#define ALL(x) (x).begin(), (x).end()

using ll = long long;
#ifndef EPS
const double eps = 1e-10;
#else
const double eps = EPS;
#endif
#line 2 "abc456/D/main.cpp"

const ll MOD = 998244353;
using mint = modint998244353;

void solve(std::string S) {
    ll N = S.size();
    vector dp(N + 1, vector<mint>(4));
    dp[0][3] = 1;
    for (ll i = 0; i < N; i++) {
        for (ll j = 0; j < 4; j++) {
            dp[i + 1][j] += dp[i][j];
        }
        ll c = S[i] - 'a';
        for (ll j = 0; j < 4; j++) {
            if (j == c) continue;
            dp[i + 1][c] += dp[i][j];
        }
    }
    cout << (dp[N][0] + dp[N][1] + dp[N][2]).val() << endl;
}

int main() {
    std::string S;
    std::cin >> S;
    solve(S);
    return 0;
}

Submission Info

Judge Result