[20251107] BOJ / P4 / 트리와 XOR / 권혁준

khj20006/202511/07 BOJ P4 트리와 XOR.md

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+```cpp
+#include <bits/stdc++.h>
+using namespace std;
+using ll = long long;
+
+int N;
+vector<vector<int>> v;
+vector<ll> a, d, s, u;
+
+void dfs1(int n, int p) {
+    s[n] = 1;
+    for(int i:v[n]) if(i != p) {
+        dfs1(i,n);
+        s[n] += s[i];
+        d[n] += d[i] + (a[n]^a[i]) * s[i];
+    }
+}
+
+void dfs2(int n, int p) {
+    if(n != 1) u[n] = u[p] + d[p] - d[n] + (a[n]^a[p]) * (N - 2 * s[n]);
+    for(int i:v[n]) if(i != p) dfs2(i,n);
+}
+
+int main() {
+    cin.tie(0)->sync_with_stdio(0);
+
+    int T;
+    for(cin>>T;T--;) {
+        cin>>N;
+        a = vector<ll>(N+1);
+        d = vector<ll>(N+1);
+        s = vector<ll>(N+1);
+        u = vector<ll>(N+1);
+        v = vector<vector<int>>(N+1);
+        for(int i=1;i<=N;i++) cin>>a[i];
+        for(int i=1,p,q;i<N;i++) {
+            cin>>p>>q;
+            v[p].push_back(q);
+            v[q].push_back(p);
+        }
+        dfs1(1,0);
+        dfs2(1,0);
+        for(int i=1;i<=N;i++) cout<<d[i]+u[i]<<' ';
+        cout<<'\n';
+    }
+
+}
+```