update

src/2/P2420.cpp

@@ -0,0 +1,44 @@
+#include <cstdint>
+#include <iostream>
+#include <utility>
+#include <vector>
+
+using ll = int64_t;
+
+template<class T>
+T input(){
+    T t;
+    std::cin>>t;
+    return t;
+}
+
+constexpr ll maxn = 100000;
+const ll n = input<ll>();
+std::vector<std::pair<ll, ll>> edg[maxn+5];
+ll xo[maxn+5];
+
+void dfs(ll f,ll now){
+    for(auto const& [v,w]:edg[now]){
+        if(v==f){
+            continue;
+        }
+        xo[now]=xo[f]^w;
+        dfs(now,v);
+    }
+}
+
+int main(){
+    for(ll i=1;i<n;i++){
+        static ll u,v,w;
+        std::cin>>u>>v>>w;
+        edg[u].emplace_back(v,w);
+        edg[v].emplace_back(u,w);
+    }
+    ll m=input<ll>();
+    dfs(0,1);
+    while(m--){
+        static ll u,v;
+        std::cin>>u>>v;
+        std::cout<<(xo[u]^xo[v])<<'\n';
+    }
+}