Submission #594009

#	Time	Username	Problem	Language	Result	Execution time	Memory
594009		stevancv	JJOOII 2 (JOI20_ho_t2)	C++14	0 / 100	2073 ms	212 KiB

ho_t2

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define sp ' '
#define en '\n'
#define smin(a, b) a = min(a, b)
#define smax(a, b) a = max(a, b)
using namespace std;
const int N = 2e5 + 2;
const int mod = 1e9 + 7;
int lst[3][N], prv[N];
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n, k;
    cin >> n >> k;
    string s; cin >> s;
    vector<int> a(n);
    for (int i = 0; i < n; i++) {
        if (s[i] == 'J') a[i] = 0;
        if (s[i] == 'O') a[i] = 1;
        if (s[i] == 'I') a[i] = 2;
    }
    vector<vector<int>> wh(3, vector<int>(n + 1, -1)), pref(3, vector<int>(n, 0));
    vector<int> cnt(3);
    for (int i = 0; i < n; i++) {
        wh[a[i]][++cnt[a[i]]] = i;
        pref[a[i]][i]++;
        if (i > 0) for (int j = 0; j < 3; j++) pref[j][i] += pref[j][i - 1];
    }
    auto Get = [&] (int l, int r, int o) {
        if (l > r) return 0;
        int ans = pref[o][r];
        if (l > 0) ans -= pref[o][l - 1];
        return ans;
    };
    if (wh[0][k] == -1 || wh[1][k] == -1 || wh[2][k] == -1) {
        cout << -1 << en;
        return 0;
    }
    int ans = 1e9;
    int l = k; int r = cnt[2] - k + 1;
    while (wh[0][l] < wh[2][r]) {
        if (Get(wh[0][l] + 1, wh[2][r] - 1, 1) >= k) smin(ans, wh[2][r + k - 1] - wh[0][l - k + 1]  + 1 - 3 * k);
        if (l == cnt[0] && r == 1) break;
        if (Get(wh[0][l + 1] + 1, wh[2][r] - 1, 1) > Get(wh[0][l] + 1, wh[2][r - 1] - 1, 1) && l < cnt[0]) l++;
        else if (r < cnt[2]) r--;
    }
    if (ans == 1e9) ans = -1;
    cout << ans << en;
    return 0;
}

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