update

src/P1030/P1030.cpp

@@ -0,0 +1 @@
+int main(){}

src/P5018/P5018.cpp

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+#include <cctype>
+#include <cstdio>
+#include <iostream>
+#include <algorithm>
+
+using ll = long long;
+
+struct CinLL{
+    char c;
+    ll n,w;
+    CinLL&operator>>(ll &ref)noexcept{
+        c=0,n=0,w=1;
+        while(!isdigit(c)){
+            if(c=='-')w=-1;
+            c=getchar();
+        }
+        while(isdigit(c)){
+            n=n*10+c-'0';
+            c=getchar();
+        }
+        ref = n*w;
+        return *this;
+    }
+}cin_ll;
+
+auto &is = cin_ll;
+auto &os = std::cout;
+
+const ll max_n = 1e6+5;
+ll n, ans{1};
+ll weight[max_n],l_son[max_n],r_son[max_n];
+
+ll dfs(const ll a,const ll b,const ll sum)noexcept{
+    if(a==-1&&b==-1){
+        return 0;
+    }else if((a==-1||b==-1)&&a!=b){
+        return -1;
+    }
+    if(weight[a]!=weight[b]){
+        return -1;
+    }
+    const ll ret_a {dfs(l_son[a],r_son[b],2)}, ret_b{dfs(r_son[a], l_son[b],2)};
+    if(ret_a==-1||ret_b==-1){
+        return -1;
+    }else{
+        return ret_a+ret_b+sum;
+    }
+}
+
+int main(){
+    is>>n;
+    for(ll i{1};i<=n;i++){
+        is>>weight[i];
+    }
+    for(ll i{1};i<=n;i++){
+        is>>l_son[i]>>r_son[i];
+    }
+    for(ll i{1};i<=n;i++){
+        if(const auto tmp = dfs(l_son[i],r_son[i],3);tmp!=-1){
+            ans = std::max(ans,tmp);
+        }
+    }
+    os<<ans<<'\n';
+}