Submission #642601

#	Time	Username	Problem	Language	Result	Execution time	Memory
642601		someone	JOIOJI (JOI14_joioji)	C++14	100 / 100	38 ms	7272 KiB

joioji

#include <bits/stdc++.h>
#define int long long
using namespace std;

const int N = 2e5 + 42, INF = 1e18 + 42;

int n, nb[3], val[N];
map<pair<int, int>, int> first;

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    
    cin >> n;
    for(int i = 0; i < n; i++) {
        char c; cin >> c;
        if(c == 'O')
            val[i] = 1;
        else if(c == 'I')
            val[i] = 2;
    }
    int maxi = 0;
    first[{0, 0}] = -1;
    for(int i = 0; i < n; i++) {
        nb[val[i]]++;
        if(first.find({nb[1] - nb[0], nb[2] - nb[0]}) == first.end()) {
            first[{nb[1] - nb[0], nb[2] - nb[0]}] = i;
        } else {
            maxi = max(maxi, i - first[{nb[1] - nb[0], nb[2] - nb[0]}]);
        }
    }
    cout << maxi;
}

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