Submission #878207

#	Time	Username	Problem	Language	Result	Execution time	Memory
878207		vjudge1	Martian DNA (BOI18_dna)	C++17	100 / 100	25 ms	4780 KiB

dna

#include <bits/stdc++.h>
using namespace std;

#define ll long long 
#define pb push_back

const int N = 2e5 + 4;

int n, k, r, a[N], mn[N], cnt[N];

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);

    cin >> n >> k >> r;
    for (int i = 0; i < n; ++i) { 
        cin >> a[i];
    }
    for (int i = 0; i < r; ++i) {
        int b;
        cin >> b;
        cin >> mn[b];
    }

    int ans = INT_MAX;
    int l = 0, r = 0, ok = 0;
    ++cnt[a[0]];
    for (int i = 0; i < k; ++i) {
        if (cnt[i] >= mn[i]) {
            ++ok;
        }
    }

    while (l <= r) {
        if (ok == k) {
            ans = min(ans, r - l + 1);
            if (cnt[a[l]] == mn[a[l]]) {
                --ok;
            }
            --cnt[a[l]];
            ++l;
        }
        else {
            if (r == n - 1) {
                break;
            }
            ++r;
            if (cnt[a[r]] == mn[a[r]] - 1) {
                ++ok;
            }
            ++cnt[a[r]];
        }
    }

    if (ans == INT_MAX) {
        cout << "impossible";
    }
    else {
        cout << ans;
    }

    return 0;
}

• Subtask 1: 16 / 16
• Subtask 2: 24 / 24
• Subtask 3: 28 / 28
• Subtask 4: 32 / 32