Submission #75428409

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Source Code Expand

#include <bits/stdc++.h>
#define int long long
#define ll long long
#define ull unsigned long long
#define inf 1e12
#define eps 1e-9
#define endl "\n"
#define il inline
#define ls 2*k
#define rs 2*k+1
using namespace std;
const int N=3e5+5,M=3e6+5;
const int mod=998244353;
inline int read(){
    int x=0,f=1;
    char ch=getchar();
    while(ch<'0'||ch>'9'){
        if(ch=='-') f=-1;
        ch=getchar();
    }
    while(ch>='0' && ch<='9') x=x*10+ch-'0',ch=getchar();
    return x*f;
}
string s;
int n,f[N],sum[3];
signed main(){
	ios::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	int tc=1; 
	while(tc--){
		cin>>s;
		n=s.size();
		s=" "+s; 
		for(int i=1;i<=n;i++){
			if(s[i]=='a'){
				f[i]=(sum[1]+sum[2]+1)%mod;
				sum[0]=(sum[0]+f[i])%mod;
			}
			else if(s[i]=='b'){
				f[i]=(sum[0]+sum[2]+1)%mod;
				sum[1]=(sum[1]+f[i])%mod;				
			}
			else{
				f[i]=(sum[1]+sum[0]+1)%mod;
				sum[2]=(sum[2]+f[i])%mod;
			}
		}
		cout<<(sum[0]+sum[1]+sum[2])%mod<<'\n';
	}
	
	return 0;
}

Submission Info

Judge Result