1 #include 
     
       2 #define _for(i,a,b) for(int i = (a);i < b;i ++) 3 typedef long long ll; 4 using namespace std; 5 int N; 6 int vallist[1000003]; 7 int stlist[2][1000003]; 8 int rnt = 1; 9 inline ll read()10 {11     ll ans = 0;12     char ch = getchar(), last = ' ';13     while(!isdigit(ch)) last = ch, ch = getchar();14     while(isdigit(ch)) ans = (ans << 1) + (ans << 3) + ch - '0', ch = getchar();15     if(last == '-') ans = -ans;16     return ans;17 }18 inline void write(ll x)19 {20     if(x < 0) x = -x, putchar('-');21     if(x >= 10) write(x / 10);22     putchar(x % 10 + '0');23 }24 struct TreeNode25 {26     int val;27     TreeNode *left;28     TreeNode *right;29 };30 TreeNode* build(int cur)31 {32     TreeNode* t = (TreeNode*)malloc(sizeof(TreeNode));33     t->val = vallist[cur];34     if(stlist[0][cur]==-1)35         t->left = NULL;36     else37         t->left = build(stlist[0][cur]-1);38     if(stlist[1][cur]==-1)39         t->right = NULL;40     else41         t->right = build(stlist[1][cur]-1);42     return t;43 }44 bool same(TreeNode* root1,TreeNode* root2)45 {46     if(!root1&&!root2)47         return true;48     if(!root1||!root2)49         return false;50     if(root1->val!=root2->val)51         return false;52     return same(root1->left,root2->right) && same(root1->right,root2->left);53 }54 int count(TreeNode* root)55 {56     if(!root)57         return 0;58     int k1 = count(root->left);59     int k2 = count(root->right);60     return k1+k2+1;61 }62 void f(TreeNode* root)63 {64     if(!root)65         return ;66     f(root->left);67     f(root->right);68     if(same(root,root))69         rnt = max(rnt,count(root));70 }71 int main()72 {73     TreeNode* root;74     N = read();75     _for(i,0,N)76         vallist[i] = read();77     _for(i,0,N)78         _for(j,0,2)79             stlist[j][i] = read();80     root = build(0);81     f(root);82     write(rnt);83     return 0;84 }