Brexit

input/code.cpp: In function 'int main()':
input/code.cpp:10:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d%d", &n, &m, &s, &t);
                                   ^
input/code.cpp:13:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &x, &y);
                        ^

#include <bits/stdc++.h>
using namespace std;
int n, m, s, t;
int d[200020];
int c[200020];
bool v[200020];
vector<int> a[200020];
queue<int> q;
int main() {
	scanf("%d%d%d%d", &n, &m, &s, &t);
	for (int i = 1; i <= m; i++) {
		int x, y;
		scanf("%d%d", &x, &y);
		a[x].push_back(y);
		a[y].push_back(x);
		d[x]++;
		d[y]++;
	}
	for (int i = 1; i <= n; i++) {
		c[i] = d[i];
	}
	v[t] = true;
	q.push(t);
	while (q.size()) {
		int u = q.front();
		q.pop();
		for (int i: a[u]) {
			d[i]--;
			d[u]--;
			if (v[i]) {
				continue;
			}
			if (d[i] * 2 <= c[i]) {
				q.push(i);
				v[i] = true;
			}
		}
	}
	if (v[s]) {
		printf("leave\n");
	} else {
		printf("stay\n");
	}
	return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: ACCEPTED

Test 29

Verdict: ACCEPTED

Test 30

Verdict: ACCEPTED

Test 31

Verdict: ACCEPTED

Test 32

Verdict: ACCEPTED

Test 33

Verdict: ACCEPTED

Test 34

Verdict: ACCEPTED

Test 35

Verdict: ACCEPTED