#933286 (C++17) No.1171 Runs in Subsequences

• 問題: No.1171 Runs in Subsequences
• ユーザー: ゆにぽけ
• 提出日時: 2023-12-01 22:23:54
• 言語: C++17 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 36 ms / 2,000 ms
• コード長: 3,107 bytes
• コンパイル時間: 1,398 ms
• コンパイル使用メモリ: 128,760 KB
• 実行使用メモリ: 5,376 KB
• 最終ジャッジ日時: 2024-09-26 15:58:21
• 合計ジャッジ時間: 3,009 ms
• ジャッジサーバーID （参考情報）: judge1 / judge5

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	2 ms; 5,248 KB
testcase_01	AC	2 ms; 5,376 KB
testcase_02	AC	2 ms; 5,376 KB
testcase_03	AC	2 ms; 5,376 KB
testcase_04	AC	2 ms; 5,376 KB
testcase_05	AC	2 ms; 5,376 KB
testcase_06	AC	2 ms; 5,376 KB
testcase_07	AC	2 ms; 5,376 KB
testcase_08	AC	2 ms; 5,376 KB
testcase_09	AC	2 ms; 5,376 KB
testcase_10	AC	2 ms; 5,376 KB
testcase_11	AC	2 ms; 5,376 KB
testcase_12	AC	2 ms; 5,376 KB
testcase_13	AC	2 ms; 5,376 KB
testcase_14	AC	2 ms; 5,376 KB
testcase_15	AC	35 ms; 5,376 KB
testcase_16	AC	34 ms; 5,376 KB
testcase_17	AC	36 ms; 5,376 KB
testcase_18	AC	36 ms; 5,376 KB
testcase_19	AC	36 ms; 5,376 KB
testcase_20	AC	36 ms; 5,376 KB
testcase_21	AC	36 ms; 5,376 KB

ソースコード

#include<iostream>
#include<vector>
#include<algorithm>
#include<cstring>
#include<cassert>
#include<cmath>
#include<ctime>
#include<iomanip>
#include<numeric>
#include<stack>
#include<queue>
#include<map>
#include<unordered_map>
#include<set>
#include<unordered_set>
#include<bitset>
#include<random>
#include<functional>
#include<utility>
using namespace std;
template<int m> struct modint
{
	private:
	unsigned int value;
	static constexpr int mod() {return m;}

	public:
	constexpr modint(const long long x = 0) noexcept
	{
		long long y = x;
		if(y < 0 || y >= mod())
		{
			y %= mod();
			if(y < 0) y += mod();
		}
		value = (unsigned int)y;
	}
	constexpr unsigned int val() noexcept {return value;}
	constexpr modint &operator+=(const modint &other) noexcept
	{
		value += other.value;
		if(value >= mod()) value -= mod();
		return *this;
	}
	constexpr modint &operator-=(const modint &other) noexcept
	{
		unsigned int x = value;
		if(x < other.value) x += mod();
		x -= other.value;
		value = x;
		return *this;
	}
	constexpr modint &operator*=(const modint &other) noexcept
	{
		unsigned long long x = value;
		x *= other.value;
		value = (unsigned int) (x % mod());
		return *this;
	}
	constexpr modint &operator/=(const modint &other) noexcept
	{
		return *this *= other.inverse();
	}
	constexpr modint inverse() const noexcept
	{
		assert(value);
		long long a = value,b = mod(),x = 1,y = 0;
		while(b)
		{
			long long q = a/b;
			a -= q*b; swap(a,b);
			x -= q*y; swap(x,y);
		}
		return modint(x);
	}
	constexpr modint power(long long N) const noexcept
	{
		assert(N >= 0);
		modint p = *this,ret = 1;
		while(N)
		{
			if(N & 1) ret *= p;
			p *= p;
			N >>= 1;
		}
		return ret;
	}
	constexpr modint operator+() {return *this;}
	constexpr modint operator-() {return modint() - *this;}
	constexpr modint &operator++(int) noexcept {return *this += 1;}
	constexpr modint &operator--(int) noexcept {return *this -= 1;}
	friend modint operator+(const modint& lhs, const modint& rhs) {return modint(lhs) += rhs;}
	friend modint operator-(const modint& lhs, const modint& rhs) {return modint(lhs) -= rhs;}
	friend modint operator*(const modint& lhs, const modint& rhs) {return modint(lhs) *= rhs;}
	friend modint operator/(const modint& lhs, const modint& rhs) {return modint(lhs) /= rhs;}
	friend ostream &operator<<(ostream &os,const modint &x) {return os << x.value;}
};
/* using mint = modint<998244353>; */
using mint = modint<1000000007>;
string S;
mint dp[2][27],way[2][27];
void solve()
{
	cin >> S;
	int N = (int)S.size();
	int cur = 0;
	way[cur][26] = 1;
	for(int i = 0;i < N;i++)
	{
		int nxt = 1-cur;
		for(int j = 0;j <= 26;j++) dp[nxt][j] = way[nxt][j] = 0;
		int c = S[i] - 'a';
		for(int j = 0;j <= 26;j++)
		{
			dp[nxt][j] += dp[cur][j];
			dp[nxt][c] += dp[cur][j] + (j != c)*way[cur][j];
			way[nxt][j] += way[cur][j];
			way[nxt][c] += way[cur][j];
		}
		swap(cur,nxt);
	}
	mint ans = 0;
	for(int i = 0;i < 26;i++) ans += dp[cur][i];
	cout << ans << endl;
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int tt = 1;
	/* cin >> tt; */
	while(tt--) solve();
}