Submission #753927

#	Time	Username	Problem	Language	Result	Execution time	Memory
753927		vjudge1	JJOOII 2 (JOI20_ho_t2)	C++14	0 / 100	1 ms	340 KiB

ho_t2

//srand(time(0)) - always changing
//order_of_key(k): Number of items strictly smaller than k .
//find_by_order(k): K-th element in a set (counting from zero).
//#pragma GCC optimize("O3,unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>

#define ordered_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
#define fopen(s) freopen(s".in","r",stdin);freopen(s".out","w",stdout)
#define all(x) (x).begin(), (x).end()
#define len(x) (int)x.size()
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define elif else if
#define F first
#define S second
#define int long long

typedef unsigned long long ull;
typedef long long ll;

using namespace std;
using namespace __gnu_pbds;

const int MOD = 1e9 + 7;
const int N = 2e5 + 7;
const int P = 911;
const ll INF = 1e18;

int gcd(int a, int b) {
	while (b) {
		a %= b;
		swap (a, b);
	}
	return a;
}

ll __sqrt(ll x) {
	ll result = 0;
	for (ll k = 1ll << 30; k != 0; k >>= 1) {
		if ((result + k) * (result + k) <= x) {
			result += k;
		}
	}
	return result;
}

int j[N], o[N], i[N];

void solve() {
	int n, k, numj = 0, numo = 0, numi = 0, ans = INF;
	string s;
	cin >> n >> k >> s;
	for (int idx = 0; idx < n; idx++) {
		if (s[idx] == 'J') {
			j[++numj] = idx;
		}
		if (s[idx] == 'O') {
			o[++numo] = idx;
		}
		if (s[idx] == 'I') {
			i[++numi] = idx;
		}
	}
	for (int idx = 0; idx + k - 1 <= numj; idx++) {
//		cout << idx << '\n';
		int l = 1, r = numo, need = j[idx + k - 1];
		while (l <= r) {
			int m = l + r >> 1;
			if (o[m] < need) l = m + 1;
			else r = m - 1;
		}
		if (o[l] < need || l + k - 1 > numo) {
			break;
		}
		need = o[l + k - 1];
		l = 1;
		r = numi;
		while (l <= r) {
			int m = l + r >> 1;
			if (i[m] < need) l = m + 1;
			else r = m - 1;
		}
		if (i[l] < need || l + k - 1 > numi) {
			break;
		} else {
			ans = min(ans, i[l + k - 1] - j[idx] + 1 - k * 3);
//			cout << idx << ' ' << j[idx] << ' ' << j[idx + k - 1] << ' ' << i[l] << ' ' << i[l + k - 1] << '\n';
		}
//		cout << idx << '\n';
	}
	if (ans == INF) ans = -1;
	cout << ans;
}

const bool Cases = 0;

signed main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int TT = 1;
	if (Cases) cin >> TT;
	while (TT--) {
		solve();
	}
}

Compilation message (stderr)

ho_t2.cpp: In function 'void solve()':
ho_t2.cpp:72:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   72 |    int m = l + r >> 1;
      |            ~~^~~
ho_t2.cpp:83:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   83 |    int m = l + r >> 1;
      |            ~~^~~

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