Submission #653681

#	Time	Username	Problem	Language	Result	Execution time	Memory
653681		veiga	Martian DNA (BOI18_dna)	C++17	100 / 100	37 ms	7116 KiB

dna

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

#define int long long
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
#define pb push_back
#define F first
#define S second
#define endl "\n"
const int INF = 1e9+10;
const int MOD = 1e9+7;

int n, k, t;
int v[200020];
int need[200020]; 

int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    cin >> n >> k >> t;
    for(int i = 0; i < n; i++) {
        cin >> v[i];
    }
    for(int i = 0; i < t; i++) {
        int a, b; cin >> a >> b;
        need[a] = b; 
    }
    int l = 0, r = 0, ok = 0;
    int cnt[200020] = {};
    bool okay[200020] = {};
    cnt[v[r]]++;
    int resp = INF;
    if(need[v[r]] != 0 and cnt[v[r]] >= need[v[r]]) {
        ok++;
        okay[v[r]] = true;
    } 
    while(r < n) {
        // cout << l << " " << r << endl;
        // cout << v[l] << " " << v[r] << endl;
        // cout << ok << endl << endl;
        if(ok == t) {
            resp = min(resp, r - l + 1);
            cnt[v[l]]--;
            if(need[v[l]] and cnt[v[l]] < need[v[l]] and okay[v[l]]) {
                ok--;
                okay[v[l]] = false;
            }
            l++;
        } else {
            r++;
            cnt[v[r]]++;
            if(need[v[r]] and cnt[v[r]] >= need[v[r]] and !okay[v[r]]) {
                ok++;
                okay[v[r]] = true;
            }
        }
    }
    if(resp == INF) cout << "impossible" << endl;
    else cout << resp << endl;

    return 0;
}

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