Submission #596807

#	Time	Username	Problem	Language	Result	Execution time	Memory
596807		penguinhacker	Martian DNA (BOI18_dna)	C++17	100 / 100	372 ms	12528 KiB

dna

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

#define ll long long
#define ar array

const int mxN=2e5;
int n, k, r, a[mxN], cnt[mxN];
set<ar<int, 2>> s;

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> n >> k >> r;
	for (int i=0; i<n; ++i)
		cin >> a[i];
	while(r--) {
		int x, y;
		cin >> x >> y;
		cnt[x]=y;
		s.insert({y, x});
	}
	for (int i=0; i<k; ++i)
		if (!cnt[i])
			s.insert({0, i});
	int ans=69696969;
	for (int l=0, r=0; r<n; ++r) {
		s.erase({cnt[a[r]], a[r]});
		s.insert({--cnt[a[r]], a[r]});
		if ((*s.rbegin())[0]>0)
			continue;
		while(cnt[a[l]]<0) {
			s.erase({cnt[a[l]], a[l]});
			s.insert({++cnt[a[l]], a[l++]});
		}
		ans=min(ans, r-l+1);
	}
	if (ans==69696969) {
		cout << "impossible";
		return 0;
	}
	cout << ans;
	return 0;
}

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