Submission #1108785

#	Time	Username	Problem	Language	Result	Execution time	Memory
1108785		Roumak77	JJOOII 2 (JOI20_ho_t2)	C++17	100 / 100	27 ms	5764 KiB

ho_t2

#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
#pragma GCC optimize("-Ofast")
#include <bits/stdc++.h>
#include <algorithm>
#include <iostream>
#include <vector>
#include <limits>
#include <cmath>
#include <stack>
#include <queue>
#include <map>
#include <math.h>
using namespace std;

using ll = long long;

void solve(){
    ll n, k;
    string s;

    cin >> n >> k;
    cin >> s;

    // Use while loop and do dp

    vector<ll> Os(n + 1, 0);
    vector<ll> Js(n + 1, 0);
    vector<ll> Is(n + 1, 0);

    for(ll i = 0; i < n; i++){
        Os[i + 1] = Os[i];
        Js[i + 1] = Js[i];
        Is[i + 1] = Is[i];
        if(s[i] == 'O'){
            Os[i + 1]++;
        }else if(s[i] == 'J'){
            Js[i + 1]++;
        }else{
            Is[i + 1]++;
        }
    }



    ll Curr_min = 1E9;

    for(ll i = 0; i < n; i++){
        ll temp = 0;
        if(Js[i + 1] < k){
            continue;
        }

        ll l = 0;
        ll r = i + 1;

        while(l + 1 < r){
            ll mid = (l + r)/2;

            if(Js[i + 1] - Js[mid] >= k){
                l = mid;
            }else{
                r = mid;
            }

        }
        temp += i - l + 1 - k;
        //cout << temp << endl;
        ll new_start = -1;
        l = i;
        r = n;
        while(l + 1 < r){
            ll mid = (l + r)/2;

            if(Os[mid] - Os[i] >= k){
                r = mid;
            }else{
                l = mid;
            }

        }

        temp += r - i - 1 - k;
        //cout << temp << endl;
        new_start = r;
        if(Is[n] - Is[new_start] < k){
            continue;
        }

        l = new_start;
        r = n;
        while(l + 1 < r){
            ll mid = (l + r)/2;

            if(Is[mid] - Is[new_start] < k){
                l = mid;
            }else{
               r = mid;
            }

        }

        temp += r - new_start - k;
        //cout << temp << endl;
        Curr_min = min(Curr_min, max(temp, 0LL));

    }
    if(Curr_min == 1E9){
        cout << -1;
    }else{
        cout << Curr_min;

    }





}



int main(){

    ios_base::sync_with_stdio(false);
    cout.tie(0);
    cin.tie(0);

    ll t = 1;

    while(t--){
        solve();
    }
}

• Subtask 1: 1 / 1
• Subtask 2: 12 / 12
• Subtask 3: 87 / 87