#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int n, m, col[100100], chk[200200];
vector<array<int, 2>> v[100100], odd, even;
int in[100100], out[100100], t[200200], cnt;
void dfs(int u, int p, int pid, int c) {
col[u] = c, in[u] = ++cnt;
for(auto [x, id] : v[u]) if(!chk[id]) {
chk[id] = 1;
if(col[x] == -1) {
dfs(x, u, id, c^1);
continue;
}
if(col[x] != c) even.push_back({u, x});
else odd.push_back({u, x});
}
out[u] = ++cnt;
}
void update(int b, int c) {
while(b <= 2*n) t[b] += c, b += b & -b;
}
int find(int b) {
int re = 0;
while(b) re += t[b], b -= b & -b;
return re;
}
int main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n >> m;
for(int i=1;i<=m;i++) {
int x, y; cin >> x >> y;
v[x].push_back({y, i}), v[y].push_back({x, i});
}
memset(col, -1, sizeof col);
for(int i=1;i<=n;i++) if(!in[i]) dfs(i, 0, 0, 0), update(in[i], 3*m), update(in[i]+1, -3*m);
for(auto [x, y] : even) update(in[y]+1, -1), update(in[x]+1, 1);
for(auto [x, y] : odd) update(in[y]+1, 1), update(in[x]+1, -1);
int cnt = 0;
for(int i=2;i<=n;i++) if(find(in[i])-find(out[i]) == odd.size()) cnt++;
cout << cnt + (odd.size() == 1);
}
Compilation message
voltage.cpp: In function 'int main()':
voltage.cpp:51:55: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
51 | for(int i=2;i<=n;i++) if(find(in[i])-find(out[i]) == odd.size()) cnt++;
| ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
4952 KB |
Output is correct |
2 |
Correct |
1 ms |
4956 KB |
Output is correct |
3 |
Correct |
2 ms |
4956 KB |
Output is correct |
4 |
Correct |
1 ms |
4956 KB |
Output is correct |
5 |
Correct |
2 ms |
4956 KB |
Output is correct |
6 |
Correct |
2 ms |
4956 KB |
Output is correct |
7 |
Correct |
1 ms |
4956 KB |
Output is correct |
8 |
Correct |
1 ms |
4956 KB |
Output is correct |
9 |
Correct |
2 ms |
4956 KB |
Output is correct |
10 |
Correct |
2 ms |
4956 KB |
Output is correct |
11 |
Correct |
2 ms |
5088 KB |
Output is correct |
12 |
Correct |
2 ms |
5088 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
24 ms |
10040 KB |
Output is correct |
2 |
Correct |
35 ms |
14672 KB |
Output is correct |
3 |
Correct |
23 ms |
9932 KB |
Output is correct |
4 |
Correct |
40 ms |
16472 KB |
Output is correct |
5 |
Correct |
4 ms |
5720 KB |
Output is correct |
6 |
Correct |
33 ms |
12632 KB |
Output is correct |
7 |
Correct |
37 ms |
18516 KB |
Output is correct |
8 |
Correct |
38 ms |
18520 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
20 ms |
9676 KB |
Output is correct |
2 |
Correct |
35 ms |
18572 KB |
Output is correct |
3 |
Correct |
28 ms |
18512 KB |
Output is correct |
4 |
Correct |
2 ms |
5208 KB |
Output is correct |
5 |
Correct |
27 ms |
13400 KB |
Output is correct |
6 |
Correct |
31 ms |
9820 KB |
Output is correct |
7 |
Correct |
45 ms |
13860 KB |
Output is correct |
8 |
Correct |
40 ms |
15456 KB |
Output is correct |
9 |
Correct |
35 ms |
15492 KB |
Output is correct |
10 |
Correct |
33 ms |
13648 KB |
Output is correct |
11 |
Correct |
29 ms |
9820 KB |
Output is correct |
12 |
Correct |
40 ms |
12116 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
37 ms |
13584 KB |
Output is correct |
2 |
Correct |
48 ms |
22680 KB |
Output is correct |
3 |
Correct |
4 ms |
4952 KB |
Output is correct |
4 |
Correct |
40 ms |
15416 KB |
Output is correct |
5 |
Correct |
39 ms |
16980 KB |
Output is correct |
6 |
Correct |
41 ms |
15516 KB |
Output is correct |
7 |
Correct |
77 ms |
19328 KB |
Output is correct |
8 |
Correct |
82 ms |
19796 KB |
Output is correct |
9 |
Correct |
79 ms |
17292 KB |
Output is correct |
10 |
Correct |
78 ms |
21244 KB |
Output is correct |
11 |
Correct |
66 ms |
17612 KB |
Output is correct |
12 |
Correct |
71 ms |
21064 KB |
Output is correct |
13 |
Correct |
55 ms |
16200 KB |
Output is correct |
14 |
Correct |
71 ms |
21712 KB |
Output is correct |
15 |
Correct |
83 ms |
21508 KB |
Output is correct |
16 |
Correct |
62 ms |
19648 KB |
Output is correct |
17 |
Correct |
63 ms |
18888 KB |
Output is correct |
18 |
Correct |
59 ms |
18884 KB |
Output is correct |