Submission #1129373

#	Time	Username	Problem	Language	Result	Execution time	Memory
1129373		mnbvcxz123	Teleporters (IOI08_teleporters)	C++20	100 / 100	243 ms	14292 KiB

teleporters

#include <stdio.h>
#include <queue>
using namespace std;
const int maxp = 2e6 + 1;

int tel[2000005], n, m;
bool vis[2000005];
priority_queue<int> pq;

int main(){
	vis[maxp] = 1;
	for(int i=0; i<maxp; i++){
		tel[i] = i+1;
	}
	scanf("%d %d",&n,&m);
	for(int i=0; i<n; i++){
		int s, e;
		scanf("%d %d",&s,&e);
		tel[s-1] = e;
		tel[e-1] = s;
	}
	int len = -1;
	for(int i=0; i<maxp; i++){
		if(!vis[i]){
			int pos = i, ret = 0;
			while(!vis[pos]){
				vis[pos] = 1;
				if(tel[pos] != pos + 1) ret++;
				pos = tel[pos];
			}
			if(len == -1) len = ret;
			else pq.push(ret);
		}
	}
	while(!pq.empty() && m--){
		len += pq.top() + 2;
		pq.pop();
	}
	len += (m + 1) / 2;
	len += (m / 2) * 3;
	printf("%d",len);
}

Compilation message (stderr)

teleporters.cpp: In function 'int main()':
teleporters.cpp:15:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |         scanf("%d %d",&n,&m);
      |         ~~~~~^~~~~~~~~~~~~~~
teleporters.cpp:18:22: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |                 scanf("%d %d",&s,&e);
      |                 ~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5
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• Subtask 19: 5 / 5
• Subtask 20: 5 / 5