제출 #753857

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
753857		vjudge1	JJOOII 2 (JOI20_ho_t2)	C++17	0 / 100	1 ms	212 KiB

ho_t2

#include <bits/stdc++.h>
 
#define int long long
#define ff first
#define ss second
#define pb push_back

using namespace std;

const int N = 2e5+10;
const int INF = 1e18;

int po[N];
int so[N];
int si[N];
int pj[N];
int n,k;
string s;

void polve(){
    cin>>n>>k;
    cin>>s;
    if(s[n-1] == 'I') si[n-1] = 1;
    for(int i = n-2;i>=0;i--){
        if(s[i] == 'I') si[i] = si[i+1]+1;
        else si[i] = si[i+1];
    }
    if(s[0] == 'J') pj[0] = 1;
    for(int i = 1;i<n;i++){
        if(s[i] == 'J') pj[i] = pj[i-1]+1;
        else pj[i] = pj[i-1];
    }
    for(int i = 1;i<n;i++){
        if(s[i] == 'O' && pj[i]>=k) po[i] = po[i-1]+1;
        else po[i] = po[i-1];
    }
    for(int i = n-1;i>=0;i--){
        if(s[i] == 'O' && si[i]>=k)  so[i] = so[i+1]+1;
        else so[i] = so[i+1];
    }
    bool ok = 0;
    bool ok1 = 0;
    for(int i=0;i<n;i++){
        if(po[i] != 0) ok = 1;
        if(so[i] != 0) ok1 = 1;
    }
    if(!ok || !ok1){
        cout<<-1;
        return;
    }
    // for(int i = 0;i<n;i++){
    //     cout<<pj[i]<<' ';
    // }
    // cout<<'\n';
    // for(int i = 0;i<n;i++){
    //     cout<<si[i]<<' ';
    // }
    // cout<<'\n';
    // for(int i = 0;i<n;i++){
    //     cout<<po[i]<<' ';
    // }
    // cout<<'\n';
    // for(int i = 0;i<n;i++){
    //     cout<<so[i]<<' ';
    // }
    // cout<<'\n';
    int pos1 = -1;
    int pos2 = -1;
    for(int i= 0;i<n;i++){
        if(so[i] == 0 || po[i] == k){
            int x = si[i]-k+1;
            for(int j = i;j<n;j++){
                if(si[j] == x && s[j] == 'I'){
                    pos2 = j;
                    break;
                }
            }
            break;
        }
    }
    for(int i= n-1;i>=0;i--){
        if(po[i] == 0 || so[i] == k){
            int x = pj[i]-k+1;
            for(int j = i;j>=0;j--){
                if(pj[j] == x && s[j] == 'J'){
                    pos1 = j;
                    break;
                }
            }
            break;
        }
    }
    cout<<pos2-pos1+1-k*3;
}
signed main(){
    // freopen("herding.in","r",stdin);  
    // freopen("herding.out","w",stdout);
    int t = 1;
    // cin>>t;   
    for(int i = 1;i<=t;i++){
        // cout<<"Case "<<i<<":\n";
        polve();
    }
}

• Subtask 1: 0 / 1
• Subtask 2: 0 / 12
• Subtask 3: 0 / 87