Submission #754032

#	Time	Username	Problem	Language	Result	Execution time	Memory
754032		vjudge1	JJOOII 2 (JOI20_ho_t2)	C++17	0 / 100	3 ms	4948 KiB

ho_t2

//gm  --- akezhon  
#include <bits/stdc++.h>
//#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define int long long
#define pb push_back
#define F first
#define S second
#define all(v) v.begin(),v.end()
#define pii pair<int,int> 
using namespace std;
int n, k, mn;
string s;
vector <int> pj(200005), po(200005), pi(200005);
void emash(){
	
	cin >> n >> k >> s;
	if ( n == 3 ){
		if ( k == 1 && s == "JOI" )cout << 0;
		else cout << -1;
		return;
	}
	for(int i=0; i < n; i++){
		if ( 0 < i ){
			pj[i] = pj[i-1];
			po[i] = po[i-1];
			pi[i] = pi[i-1];
		}
		if ( s[i] == 'J' )pj[i]++;
		if ( s[i] == 'O' )po[i]++;
		if ( s[i] == 'I' )pi[i]++;
	}
	mn = 1e9;
	for(int i=0; i < n; i++){
		if ( s[i] != 'J' )continue;
		int l=i, r=n, f=pj[i]+k-1;
		while(l < r-1){
			int m = (l+r)/2;
			if ( f <= pj[m] )r = m;
			else l = m;
		}
		if ( r == n )continue;
		l = r+1;
		r = n;
		f = po[l-1]+k;
		while(l < r-1){
			int m = (l+r)/2;
			if ( f <= po[m] )r = m;
			else l = m;
		}
		if ( r == n )continue;
		l = r+1;
		r = n;
		f = pi[l-1]+k;
		while(l < r-1){
			int m = (l+r)/2;
			if ( f <= pi[m] )r = m;
			else l = m;
		}
		if ( r == n )continue;
		//cout << 3 << ' ' << r << '\n';
		mn = min(mn, r-i+1-3*k);
	}
	cout << (mn == 1e9 ? -1 : mn);
}
signed main(){

	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	
	//freopen("262144.in", "r", stdin);
	//freopen("262144.out", "w", stdout);
	
	int RealName=1;
	//cin >> RealName;
	int C=0;
	while(RealName--){
		//cout << "Case " << ++C << ":\n";
		emash();
	}

return 0;
}

Compilation message (stderr)

ho_t2.cpp: In function 'int main()':
ho_t2.cpp:77:6: warning: unused variable 'C' [-Wunused-variable]
   77 |  int C=0;
      |      ^

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