#563591 (C++14) No.1171 Runs in Subsequences

• 問題: No.1171 Runs in Subsequences
• ユーザー: kotatsugame
• 提出日時: 2020-10-08 23:05:32
• 言語: C++14 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 31 ms / 2,000 ms
• コード長: 2,357 bytes
• コンパイル時間: 599 ms
• コンパイル使用メモリ: 65,920 KB
• 実行使用メモリ: 5,376 KB
• 最終ジャッジ日時: 2024-07-20 06:12:37
• 合計ジャッジ時間: 1,950 ms
• ジャッジサーバーID （参考情報）: judge5 / judge1

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	3 ms; 5,376 KB
testcase_05	AC	2 ms; 5,376 KB
testcase_06	AC	2 ms; 5,376 KB
testcase_07	AC	1 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	3 ms; 5,376 KB
testcase_14	AC	2 ms; 5,376 KB
testcase_15	AC	30 ms; 5,376 KB
testcase_16	AC	29 ms; 5,376 KB
testcase_17	AC	31 ms; 5,376 KB
testcase_18	AC	31 ms; 5,376 KB
testcase_19	AC	30 ms; 5,376 KB
testcase_20	AC	30 ms; 5,376 KB
testcase_21	AC	30 ms; 5,376 KB

コンパイルメッセージ

a.cpp:7:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]

ソースコード

#line 1 "a.cpp"
#include<iostream>
using namespace std;
#line 3 "/home/kotatsugame/library/math/modint.cpp"
#include<utility>
template<int m>
struct modint{
	unsigned int x;
	constexpr modint()noexcept:x(){}
	constexpr modint(long long _x)noexcept:x((_x%=m)<0?_x+m:_x){}
	constexpr unsigned int val()const noexcept{return x;}
	constexpr modint&operator++()noexcept{if(++x==m)x=0;return*this;}
	constexpr modint&operator--()noexcept{if(x==0)x=m;--x;return*this;}
	constexpr modint operator++(int)noexcept{modint res=*this;++*this;return res;}
	constexpr modint operator--(int)noexcept{modint res=*this;--*this;return res;}
	constexpr modint&operator+=(const modint&a)noexcept{x+=a.x;if(x>=m)x-=m;return*this;}
	constexpr modint&operator-=(const modint&a)noexcept{if(x<a.x)x+=m;x-=a.x;return*this;}
	constexpr modint&operator*=(const modint&a)noexcept{x=(unsigned long long)x*a.x%m;return*this;}
	constexpr modint&operator/=(const modint&a)noexcept{return*this*=a.inv();}
	constexpr modint operator+()const noexcept{return*this;}
	constexpr modint operator-()const noexcept{return modint()-*this;}
	constexpr modint pow(long long n)const noexcept
	{
		if(n<0)return pow(-n).inv();
		modint x=*this,r=1;
		for(;n;x*=x,n>>=1)if(n&1)r*=x;
		return r;
	}
	constexpr modint inv()const noexcept
	{
		int s=x,t=m,x=1,u=0;
		while(t)
		{
			int k=s/t;
			s-=k*t;
			swap(s,t);
			x-=k*u;
			swap(x,u);
		}
		return modint(x);
	}
	constexpr modint operator+(const modint&a)const noexcept{return modint(*this)+=a;}
	constexpr modint operator-(const modint&a)const noexcept{return modint(*this)-=a;}
	constexpr modint operator*(const modint&a)const noexcept{return modint(*this)*=a;}
	constexpr modint operator/(const modint&a)const noexcept{return modint(*this)/=a;}
	constexpr bool operator==(const modint&a)const noexcept{return x==a.x;}
	constexpr bool operator!=(const modint&a)const noexcept{return x!=a.x;}
	friend ostream&operator<<(ostream&os,const modint&a){return os<<a.x;}
	friend istream&operator>>(istream&is,modint&a){long long v;is>>v;a=modint(v);return is;}
};
#line 4 "a.cpp"
string S;
using mint=modint<(int)1e9+7>;
mint dp[26];
main()
{
	cin>>S;
	mint ans=0;
	for(int i=0;i<S.size();i++)
	{
		mint sum=1;
		for(int j=0;j<26;j++)if(j!=S[i]-'a')sum+=dp[j];
		dp[S[i]-'a']+=sum+dp[S[i]-'a'];
		ans+=sum*mint(2).pow(S.size()-i-1);
	}
	cout<<ans<<endl;
}