Submission #118710

#	Time	Username	Problem	Language	Result	Execution time	Memory
118710		eriksuenderhauf	Teleporters (IOI08_teleporters)	C++11	100 / 100	487 ms	35020 KiB

teleporters

//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
#define mem(a,v) memset((a), (v), sizeof (a))
#define enl printf("\n")
#define case(t) printf("Case #%d: ", (t))
#define ni(n) scanf("%d", &(n))
#define nl(n) scanf("%I64d", &(n))
#define nai(a, n) for (int i = 0; i < (n); i++) ni(a[i])
#define nal(a, n) for (int i = 0; i < (n); i++) nl(a[i])
#define pri(n) printf("%d\n", (n))
#define prl(n) printf("%I64d\n", (n))
#define pii pair<int, int>
#define pil pair<int, long long>
#define pll pair<long long, long long>
#define vii vector<pii>
#define vil vector<pil>
#define vll vector<pll>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef cc_hash_table<int,int,hash<int>> ht;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> oset;
const double pi = acos(-1);
const int MOD = 1e9 + 7;
const int INF = 1e9 + 7;
const int MAXN = 2e6 + 5;
const double eps = 1e-9;
int nx[MAXN], vis[MAXN];

int main() {
	int n, m;
	scanf("%d %d", &n, &m);
	for (int i = 0 ; i < MAXN; i++)
		nx[i] = i + 1;
	vis[MAXN - 1] = 1;
	for (int i = 0; i < n; i++) {
		int u, v;
		scanf("%d %d", &u, &v);
		nx[u - 1] = v;
		nx[v - 1] = u;
	}
	int ans = -1;
	priority_queue<int> pq;
	for (int i = 0; i < MAXN; i++) {
		if (vis[i]) continue;
		int cur = i, cnt = 0;
		while (!vis[cur]) {
			vis[cur] = 1;
			if (nx[cur] != cur + 1)
				cnt++;
			cur = nx[cur];
		}
		if (ans == -1)
			ans = cnt;
		else
			pq.push(cnt);
	}
	while (!pq.empty() && m > 0) {
		m--;
		ans += pq.top() + 2;
		pq.pop();
	}
	ans += (m + 1) / 2 + (m / 2) * 3;
	pri(ans);
    return 0;
}

Compilation message (stderr)

teleporters.cpp: In function 'int main()':
teleporters.cpp:41:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~~
teleporters.cpp:47:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &u, &v);
   ~~~~~^~~~~~~~~~~~~~~~~

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