Submission #1025002

#	Time	Username	Problem	Language	Result	Execution time	Memory
1025002		phoenix	Martian DNA (BOI18_dna)	C++17	100 / 100	135 ms	18576 KiB

dna

#include <bits/stdc++.h>

using namespace std;

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    int n, k, r;
    cin >> n >> k >> r;
    int a[n];
    for (int i = 0; i < n; i++) 
        cin >> a[i];
    
    int q[k] = {};

    for (int i = 0; i < r; i++) {
        int b, c;
        cin >> b >> c;
        q[b] = c;
    }

    set<pair<int, int>> st;
    for (int i = 0; i < k; i++) {
        if (q[i]) 
            st.insert({-1, i});
    }
    vector<vector<int>> p(k);
    
    auto get = [&](int d) {
        return ((int)p[d].size() < q[d] ? -1 : p[d][(int)p[d].size() - q[d]]);
    };

    int res = n + 1;

    for (int i = 0; i < n; i++) {
        if (q[a[i]]) {
            assert(st.count({get(a[i]), a[i]}));
            st.erase({get(a[i]), a[i]});
        }
        p[a[i]].push_back(i);
        if (q[a[i]]) {
            st.insert({get(a[i]), a[i]});
        }
        if (st.begin()->first != -1) 
            res = min(res, i - st.begin()->first + 1);
    }
    if (res == n + 1) {
        cout << "impossible\n";
        return 0;
    }
    cout << res << '\n';
    return 0;
}

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