mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
45 lines
1.2 KiB
C++
45 lines
1.2 KiB
C++
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#include <cstdio>
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#include <cstring>
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#include <algorithm>
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#include <vector>
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#include <queue>
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using namespace std;
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const int MAXN = 5e5 + 10;
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const int INF = 0x3f3f3f3f;
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int w[MAXN];
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int cnt[MAXN];
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int deg[MAXN];
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vector<int> G[MAXN];
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int n;
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int BFS(void) {
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queue<int> Q; int ret = 0;
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for (int i=1; i<=n; ++i) cnt[i] = 1;
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for (int i=1; i<=n; ++i) {
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if (!deg[i]) Q.push (i);
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}
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while (!Q.empty ()) {
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int u = Q.front (); Q.pop ();
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ret = max (ret, cnt[u]);
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for (int i=0; i<G[u].size (); ++i) {
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int v = G[u][i];
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cnt[v] += cnt[u];
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if (!(--deg[v])) Q.push (v);
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}
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}
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return ret;
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}
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int main(void) {
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while (scanf ("%d", &n) == 1) {
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for (int i=1; i<=n; ++i) scanf ("%d", &w[i]);
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for (int i=1; i<=n; ++i) G[i].clear ();
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memset (deg, 0, sizeof (deg));
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for (int i=1; i<=n-1; ++i) {
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int u, v; scanf ("%d%d", &u, &v);
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if (w[u] < w[v]) swap (u, v);
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G[u].push_back (v); deg[v]++;
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}
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printf ("%d\n", BFS ());
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}
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return 0;
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}
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