#include <bits/stdc++.h>
using namespace std;
vector<int> edge[500005], vec[500005];
int dfn[500005], dfnn, C[500005], par[500005], dep[500005], D[500005];
struct UF {
int par[500005];
UF() { iota(par, par + 500005, 0); }
int fnd(int x) { return par[x] == x ? x : par[x] = fnd(par[x]); }
} u1;;
void dfs(int x, int p) {
par[x] = p;
dep[x] = dep[p] + 1;
dfn[x] = ++dfnn;
for (auto i : edge[x]) {
if (i == p) continue;
dfs(i, x);
}
}
int main() {
ios_base::sync_with_stdio(0), cin.tie(0);
int N, M; cin >> N >> M;
for (int i = 1; i < N; ++i) {
int x, y; cin >> x >> y;
edge[x].push_back(y);
edge[y].push_back(x);
}
dfs(1, 1);
for (int i = 1; i <= N; ++i) {
cin >> C[i];
vec[C[i]].push_back(i);
}
for (int i = 1; i <= N; ++i) D[i] = edge[i].size();
for (int i = 1; i <= M; ++i) {
sort(vec[i].begin(), vec[i].end(), [&](int a, int b) {
return dfn[a] < dfn[b];
});
for (int j = 0; j + 1 < vec[i].size(); ++j) {
int x = u1.fnd(vec[i][j]), y = u1.fnd(vec[i][j + 1]);
while (x != y) {
int a, b;
if (dep[x] < dep[y]) {
int t = u1.fnd(par[y]);
if (y != t) {
D[y]--;
D[t]--;
u1.par[y] = t;
D[t] += D[y];
}
y = u1.fnd(y);
}
else {
int t = u1.fnd(par[x]);
if (x != t) {
D[x]--;
D[t]--;
u1.par[x] = t;
D[t] += D[x];
}
x = u1.fnd(x);
}
}
}
}
int ans = 0;
for (int i = 1; i <= N; ++i) ans += D[i] == 1;
cout << ans / 2;
return 0;
}
Compilation message
mergers.cpp: In function 'int main()':
mergers.cpp:41:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int j = 0; j + 1 < vec[i].size(); ++j) {
~~~~~~^~~~~~~~~~~~~~~
mergers.cpp:44:9: warning: unused variable 'a' [-Wunused-variable]
int a, b;
^
mergers.cpp:44:12: warning: unused variable 'b' [-Wunused-variable]
int a, b;
^
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
28 ms |
25848 KB |
Output is correct |
2 |
Incorrect |
27 ms |
25848 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
28 ms |
25848 KB |
Output is correct |
2 |
Incorrect |
27 ms |
25848 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
28 ms |
25848 KB |
Output is correct |
2 |
Incorrect |
27 ms |
25848 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
106 ms |
31984 KB |
Output is correct |
2 |
Incorrect |
110 ms |
34456 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
28 ms |
25848 KB |
Output is correct |
2 |
Incorrect |
27 ms |
25848 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |