#include <bits/stdc++.h>
#ifdef local
#define safe std::cerr<<__PRETTY_FUNCTION__<<" line "<<__LINE__<<" safe\n"
#define debug(a...) qqbx(#a, a)
template <typename ...T> void qqbx(const char *s, T ...a) {
int cnt = sizeof...(T);
((std::cerr << "\033[1;32m(" << s << ") = (") , ... , (std::cerr << a << (--cnt ? ", " : "\033[0m)\n")));
}
#else
#define debug(...) ((void)0)
#define safe ((void)0)
#endif // local
#define all(v) begin(v),end(v)
using namespace std;
const int64_t INF = 1e18;
const int maxn = 500025;
struct Dsu {
int pa[maxn], rk[maxn];
int anc(int x) { return x==pa[x] ? x : pa[x] = anc(pa[x]); }
void init(int n) {
for (int i = 1; i <= n; i++)
pa[i] = i, rk[i] = 0;
}
bool join(int x, int y) {
if ((x=anc(x)) == (y=anc(y))) return false;
if (rk[x] < rk[y]) swap(x, y);
return pa[y] = x, rk[x]!=rk[y] || ++rk[x];
}
} dsu;
vector<int> g[maxn];
vector<pair<int,int>> ed;
int s[maxn];
int cnt[2][maxn], has;
void dfs(int i, int p = 0) {
if (has > 0) {
dsu.join(i, p);
} else if (p) {
ed.emplace_back(i, p);
}
has -= (min(cnt[0][s[i]], cnt[1][s[i]]) > 0);
cnt[0][s[i]] -= 1;
cnt[1][s[i]] += 1;
has += (min(cnt[0][s[i]], cnt[1][s[i]]) > 0);
for (int j: g[i]) {
if (j != p) {
dfs(j, i);
}
}
has -= (min(cnt[0][s[i]], cnt[1][s[i]]) > 0);
cnt[0][s[i]] += 1;
cnt[1][s[i]] -= 1;
has += (min(cnt[0][s[i]], cnt[1][s[i]]) > 0);
}
bool vis[maxn];
int leaf = 0;
void dfs2(int i) {
debug(i);
if (g[i].size() == 1) ++leaf;
vis[i] = true;
for (int j: g[i]) {
if (!vis[j])
dfs2(j);
}
}
signed main() {
ios_base::sync_with_stdio(0), cin.tie(0);
int n, k;
cin >> n >> k;
for (int i = 1; i < n; i++) {
int a, b;
cin >> a >> b;
g[a].emplace_back(b);
g[b].emplace_back(a);
}
for (int i = 1; i <= n; i++) cin >> s[i];
for (int i = 1; i <= n; i++) ++cnt[0][s[i]];
dsu.init(n);
dfs(1);
for (int i = 1; i <= n; i++) g[i].clear();
for (auto [a, b]: ed) {
a = dsu.anc(a);
b = dsu.anc(b);
g[a].emplace_back(b);
g[b].emplace_back(a);
debug(a, b);
}
int ans = 0;
for (int i = 1; i <= n; i++) if (!vis[i]) {
leaf = 0;
dfs2(i);
debug(leaf);
ans += (leaf + 1) / 2;
}
cout << ans << '\n';
}
Compilation message
mergers.cpp: In function 'int main()':
mergers.cpp:83:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
83 | for (auto [a, b]: ed) {
| ^
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
8 ms |
12140 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
8 ms |
12140 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
8 ms |
12140 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
59 ms |
16868 KB |
Output is correct |
2 |
Correct |
69 ms |
20584 KB |
Output is correct |
3 |
Incorrect |
11 ms |
12268 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
8 ms |
12140 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |