Submission #933682

#	Time	Username	Problem	Language	Result	Execution time	Memory
933682		ByeWorld	JJOOII 2 (JOI20_ho_t2)	C++14	100 / 100	13 ms	6776 KiB

ho_t2

#include <bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define int long long
#define lf (id<<1)
#define rg ((id<<1)|1)
#define md ((l+r)>>1)
using namespace std;
typedef pair<int,int> pii;
typedef pair<string, pii> ipii;
const int INF = 1e9+10;
const int MAXN = 1e6+10;

int n, k; 
int O[MAXN], I[MAXN];
string s;
int mn = INF;
vector <int> vec;

void f(int idx, int fr){
	int l=idx, r=n, cnt=-1, mid=0;
	while(l<=r){
		mid = md;
		if(O[idx]-O[mid+1] >= k){ // ke kiri
			r = mid-1; cnt = mid;
		} else l = mid+1;
	}
	int ido = cnt;
	if(ido == -1) return;
	//cout << ido << " O\n";
	l = cnt, r=n, cnt=-1, mid=0;
	while(l<=r){
		mid = md;
		if(I[ido]-I[mid+1] >= k){
			r = mid-1; cnt = mid;
		} else l = mid+1;
	}

	if(cnt == -1) return;
	//cout << cnt << " i\n";
	mn = min(mn, cnt-fr+1 - 3*k);
}
signed main(){
	cin >> n >> k;
	cin >> s; s = '.'+s; 
	for(int i=n; i>=1; i--){
		O[i] = O[i+1] + (s[i]=='O' ? 1 : 0); 
		I[i] = I[i+1] + (s[i]=='I' ? 1 : 0);
	}
	for(int i=1; i<=n; i++){
		if(s[i] == 'J'){
			vec.pb(i);
		}
	}
	for(int i=k-1; i<vec.size(); i++){
		f(vec[i], vec[i-k+1]);
	}
	cout << (mn>n ? -1 : mn) << '\n';
}

Compilation message (stderr)

ho_t2.cpp: In function 'int main()':
ho_t2.cpp:56:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |  for(int i=k-1; i<vec.size(); i++){
      |                 ~^~~~~~~~~~~

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