Submission #625070

#	Time	Username	Problem	Language	Result	Execution time	Memory
625070		iomoon191	Teleporters (IOI08_teleporters)	C++17	40 / 100	111 ms	16460 KiB

teleporters

#include <bits/stdc++.h>
using ll = long long;
#define int ll
using namespace std;

#define sz(x) (int)(x).size()
#define foru(i, l, r) for(int i = l; i <= r; i++)
#define ford(i, l, r) for(int i = l; i >= r; i--)
#define fi first
#define se second
#define mod 998244353

#define db(x) cerr << __LINE__ << " " << #x << " " << x << "\n"
using vi = vector<int>;
using pi = pair<int, int>;

const ll N = 200005;
const ll inf = 1e18;

int n, m, w[N], e[N], vis[N], nxt[N];
vi v;

void solve(){
	cin >> n >> m;
	foru(i, 1, n){
		cin >> w[i] >> e[i];
		v.push_back(w[i]);
		v.push_back(e[i]);
	}
	sort(v.begin(), v.end());
	foru(i, 0, (n << 1) - 1){
		nxt[i] = i + 1;
	}
	nxt[n << 1] = 0;
	foru(i, 1, n){
		w[i] = lower_bound(v.begin(), v.end(), w[i]) - v.begin() + 1;
		e[i] = lower_bound(v.begin(), v.end(), e[i]) - v.begin() + 1;
		nxt[w[i] - 1] = e[i];
		nxt[e[i] - 1] = w[i];
	}
	v.clear();
	int res;
	foru(i, 0, n << 1){
		if(vis[i]) continue;
		int cnt = 0;
		for(int j = i; !vis[j]; j = nxt[j]){
			vis[j] = 1;
			cnt++;
		}
		if(!i) res = cnt;
		else v.push_back(cnt);
	}
	sort(v.begin(), v.end()); res--;
	while(m){
		if(!sz(v)) break;
		else{
			res += v.back() + 2;
			v.pop_back();
		}
		m--;
	}
	cout << res - (m >> 1) + (m << 1);
}

signed main(){
	ios_base::sync_with_stdio(0); cin.tie(0);
	int t = 1; 
	while(t--){
		solve();
	}
}

Compilation message (stderr)

teleporters.cpp: In function 'void solve()':
teleporters.cpp:53:31: warning: 'res' may be used uninitialized in this function [-Wmaybe-uninitialized]
   53 |  sort(v.begin(), v.end()); res--;
      |                            ~~~^~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 0 / 5
• Subtask 6: 0 / 5
• Subtask 7: 0 / 5
• Subtask 8: 5 / 5
• Subtask 9: 5 / 5
• Subtask 10: 5 / 5
• Subtask 11: 0 / 5
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• Subtask 14: 0 / 5
• Subtask 15: 5 / 5
• Subtask 16: 0 / 5
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• Subtask 18: 0 / 5
• Subtask 19: 0 / 5
• Subtask 20: 0 / 5