new file: P3258.cpp

P3258.cpp

@@ -0,0 +1,99 @@
+#include<bits/stdc++.h>
+#define int long long
+using namespace std;
+int n;
+int a[300005];
+int fa[300005];
+int dfn[300005];
+int son[300005];
+int dep[300005];
+int top[300005];
+int cnt[300005];
+vector<int> fri[300005];
+int dfnnow;
+struct SEG{
+    int num[1200005], lt[1200005];
+    void pu(int now) {
+        num[now] = num[now * 2] + num[now * 2 + 1];
+    }
+    void pd(int now, int nl, int nr) {
+        int nmid = (nl + nr) >> 1, l = lt[now];
+        num[now * 2] += l * (nmid - nl + 1);
+        num[now * 2 + 1] += l * (nr - nmid);
+        lt[now * 2] += l;
+        lt[now * 2 + 1] += l;
+        lt[now] = 0;
+    }
+    void add(int now, int nl, int nr, int l, int r, int nn) {
+        if(nr < l || nl > r) return;
+        if(l <= nl && nr <= r) {
+            num[now] += (nr - nl + 1) * nn;
+            lt[now] += nn;
+            return;
+        }
+        int nmid = (nl + nr) >> 1;
+        pd(now, nl, nr);
+        add(now * 2, nl, nmid, l, r, nn);
+        add(now * 2 + 1, nmid + 1, nr, l, r, nn);
+        pu(now);
+    }
+    int query(int now, int nl, int nr, int l, int r) {
+        if(nr < l || nl > r) return 0;
+        if(l <= nl && nr <= r) {
+            return num[now];
+        }
+        int nmid = (nl + nr) >> 1;
+        pd(now, nl, nr);
+        return query(now * 2, nl, nmid, l, r) + query(now * 2 + 1, nmid + 1, nr, l, r);
+    }
+}seg;
+void dfs1(int now, int from) {
+    cnt[now] = 1;
+    for(int i : fri[now]) {
+        if(i == from) continue;
+        fa[i] = now;
+        dep[i] = dep[now] + 1; 
+        dfs1(i, now);
+        cnt[now] += cnt[i];
+        if(cnt[son[now]] < cnt[i]) son[now] = i;
+    }
+}
+void dfs2(int now, int from) {
+    top[now] = from;
+    dfn[now] = ++dfnnow;
+    if(son[now]) dfs2(son[now], from);
+    for(int i : fri[now]) {
+        if(i == fa[now] || i == son[now]) continue;
+        dfs2(i, i);
+    }
+}
+void edit(int a, int b, int nn = 1) {
+    while(top[a] != top[b]) {
+        if(dep[top[a]] < dep[top[b]]) swap(a, b);
+        seg.add(1, 1, n, dfn[top[a]], dfn[a], nn);
+        a = fa[top[a]];
+    }
+    if(dep[a] < dep[b]) swap(a, b);
+    seg.add(1, 1, n, dfn[b], dfn[a], nn);
+}
+signed main() {
+    scanf("%lld", &n);
+    for(int i = 1; i <= n; ++i) {
+        scanf("%lld", &a[i]);
+    }
+    for(int i = 1, u, v; i < n; ++i) {
+        scanf("%lld%lld", &u, &v);
+        fri[u].push_back(v);
+        fri[v].push_back(u);
+    }
+    dfs1(1, -1);
+    dfs2(1, 1);
+    for(int i = 1; i < n; ++i) {
+        edit(a[i], a[i + 1]);
+        edit(a[i + 1], a[i + 1], -1);
+    }
+    for(int i = 1; i <= n; ++i) {
+        printf("%lld\n", seg.query(1, 1, n, dfn[i], dfn[i]));
+    }
+    return 0;
+}