50144. Tree Construction and Queries
難度：3/5
Second Try: 3/5 Used Time: 18:241
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66#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "tree.h"
Node* get_node(){
Node* new_node = (Node*) malloc(sizeof(Node));
new_node->data = 1, new_node->left = NULL, new_node->right = NULL;
return new_node;
}
Node *construct(Node *root, char s[MAXN]){
int n = strlen(s);
if(root == NULL){
Node* new_node = get_node();
root = new_node;
}
else{
root->data++;
}
Node* now = root;
for(int i = 0; i < n; i++){
if(s[i] == 'L'){
if(now->left == NULL){
Node* new_node = get_node();
now->left = new_node;
now = now->left;
}
else{
now = now->left;
now->data++;
}
}
else{
if(now->right == NULL){
Node* new_node = get_node();
now->right = new_node;
now = now->right;
}
else{
now = now->right;
now->data++;
}
}
}
return root;
}
int query(Node *root, char s[MAXN]){
int n = strlen(s);
if(root == NULL) return 0;
for(int i = 0; i < n; i++){
if(s[i] == 'L'){
if(root->left == NULL) return 0;
else root = root->left;
}
else{
if(root->right == NULL) return 0;
else root = root->right;
}
}
return root->data;
}