Submission #1267324

#	Time	Username	Problem	Language	Result	Execution time	Memory
1267324		trvhung	JJOOII 2 (JOI20_ho_t2)	C++20	100 / 100	9 ms	3592 KiB

ho_t2

#include <bits/stdc++.h>
// #include <ext/rope>
// #include <ext/pb_ds/assoc_container.hpp>

// using namespace __gnu_pbds;
// using namespace __gnu_cxx;
using namespace std;

// #define   ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define            ll long long
#define           ull unsigned long long
#define            ld long double
#define            pb push_back
#define  bit(mask, i) ((mask >> i) & 1)
#define            el '\n'
#define             F first
#define             S second

template <class X, class Y> bool maximize(X &x, const Y &y) { return (x < y ? x = y, 1 : 0); }
template <class X, class Y> bool minimize(X &x, const Y &y) { return (x > y ? x = y, 1 : 0); }

const int INF = 1e9;
const ll LINF = 1e18;
const int MOD = 1e9 + 7;
const int MULTI = 0;
const ld eps = 1e-9;
const int dx[4] = {0, 1, 0, -1}, dy[4] = {1, 0, -1, 0}; // R D L U
const int ddx[4] = {-1, 1, 1, -1}, ddy[4] = {1, 1, -1, -1}; // UR DR DL UL
const char cx[4] = {'R', 'D', 'L', 'U'};
const ll base = 31;
const int nMOD = 2;
const ll mods[] = {(ll)1e9 + 10777, (ll)1e9 + 19777, (ll)1e9 + 3, (ll)1e9 + 3777};

const int N = 3e5 + 5;
int n, k;
string s;
vector<pair<int, int>> J, O, I, OI;

void getP(vector<pair<int, int>> &v, char c) {
	deque<int> q; 
	int bp = 0;
	
	for (int i = n; i >= 1; --i) {
		if (s[i] != c) continue;
		q.push_front(i);
		if ((int) q.size() == k) {
			bp = i;
			break;
		}
	}

	if (bp) v.push_back(make_pair(bp, q.back()));
	for (int i = bp - 1; i >= 1; --i) {
		if (s[i] != c) continue;
		q.pop_back();
		q.push_front(i);
		v.push_back(make_pair(i, q.back()));
	}

	reverse(v.begin(), v.end());
}

void solve() {
	cin >> n >> k >> s;

	s = ' ' + s;

	getP(J, 'J');
	getP(O, 'O');
	getP(I, 'I');

	int cur = (int) I.size();
	for (int i = (int) O.size() - 1; i >= 0; --i) {
		while (cur > 0 && I[cur - 1].F > O[i].S) cur--;
		if (cur >= 0 && cur < (int) I.size()) 
			OI.push_back(make_pair(O[i].F, I[cur].S));
	}

	int res = INF;
	cur = (int) OI.size();
	reverse(OI.begin(), OI.end());

	for (int i = (int) J.size() - 1; i >= 0; --i) {
		while (cur > 0 && OI[cur - 1].F > J[i].S) cur--;
		if (cur >= 0 && cur < (int) OI.size()) 
			minimize(res, OI[cur].S - J[i].F + 1 - 3 * k);
	}

	cout << (res == INF ? -1 : res);
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    if (!MULTI) solve();
    else {
        int test; cin >> test;
        while (test--) solve();
    }
    
    return 0;
}

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