Submission #173430

#	Time	Username	Problem	Language	Result	Execution time	Memory
173430		easrui	JOIOJI (JOI14_joioji)	C++14	100 / 100	63 ms	6276 KiB

joioji

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

map<ll,int> M;
ll N,J,O,I,cnt;
int ans;
string S;

int main()
{
    ios_base::sync_with_stdio(0),cin.tie(0);
    cin >> N >> S;
    M.insert(make_pair(0,0));
    for(int i=0; i<N; i++){
        if(S[i]=='J') O--,I--;
        if(S[i]=='O') O++;
        if(S[i]=='I') I++;
        cnt = O*(N+1)+I;
        if(M.find(cnt)==M.end()) M.insert(make_pair(cnt,i+1));
    }
    for(int i=N-1; i>=0; i--){
        cnt = O*(N+1)+I;
        if(M.find(cnt)!=M.end()) ans = max(ans,i+1-M[cnt]);
        if(S[i]=='J') O++,I++;
        if(S[i]=='O') O--;
        if(S[i]=='I') I--;
    }
    cout << ans;
}

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 80 / 80