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| 1 | +#include <iostream> |
| 2 | +#include <queue> |
| 3 | +#include <string> |
| 4 | +#include <cassert> |
| 5 | + |
| 6 | +using namespace std; |
| 7 | + |
| 8 | +struct TreeNode { |
| 9 | + int val; |
| 10 | + TreeNode *left; |
| 11 | + TreeNode *right; |
| 12 | + TreeNode(int x) : val(x), left(NULL), right(NULL) {} |
| 13 | +}; |
| 14 | + |
| 15 | +class Codec { |
| 16 | +public: |
| 17 | + // Encodes a tree to a single string. |
| 18 | + string serialize(TreeNode* root) { |
| 19 | + if (root == NULL) return ""; |
| 20 | + queue<TreeNode *> q; |
| 21 | + q.push(root); |
| 22 | + TreeNode *p; |
| 23 | + string result = to_string(root->val); |
| 24 | + while (!q.empty()) { |
| 25 | + p = q.front(); |
| 26 | + q.pop(); |
| 27 | + if (p->left && p->right) { |
| 28 | + q.push(p->left); |
| 29 | + q.push(p->right); |
| 30 | + result += "," + to_string(p->left->val) + "," + to_string(p->right->val); |
| 31 | + } |
| 32 | + else if (p->left && !p->right) { |
| 33 | + q.push(p->left); |
| 34 | + result += ",L," + to_string(p->left->val); |
| 35 | + } |
| 36 | + else if (!p->left && p->right) { |
| 37 | + q.push(p->right); |
| 38 | + result += ",R," + to_string(p->right->val); |
| 39 | + } |
| 40 | + else { |
| 41 | + result += ",N"; |
| 42 | + } |
| 43 | + } |
| 44 | + return result; |
| 45 | + } |
| 46 | + |
| 47 | + // Decodes your encoded data to tree. |
| 48 | + TreeNode* deserialize(string data) { |
| 49 | + if (data.length() == 0) return NULL; |
| 50 | + vector<string> nodes = split(data, ','); |
| 51 | + auto it = nodes.begin(); |
| 52 | + TreeNode *root = new TreeNode(stoi(*(it++))); |
| 53 | + queue<TreeNode *> q; |
| 54 | + q.push(root); |
| 55 | + while (!q.empty() && it != nodes.end()) { |
| 56 | + TreeNode *p = q.front(); |
| 57 | + if (*it == "N") { |
| 58 | + it++; |
| 59 | + } |
| 60 | + else if (*it == "L") { |
| 61 | + p->left = new TreeNode(stoi(*(++it))); |
| 62 | + it++; |
| 63 | + } |
| 64 | + else if (*it == "R") { |
| 65 | + p->right = new TreeNode(stoi(*(++it))); |
| 66 | + it++; |
| 67 | + } |
| 68 | + else { |
| 69 | + p->left = new TreeNode(stoi(*(it++))); |
| 70 | + p->right = new TreeNode(stoi(*(it++))); |
| 71 | + } |
| 72 | + |
| 73 | + q.pop(); |
| 74 | + if (p->left) q.push(p->left); |
| 75 | + if (p->right) q.push(p->right); |
| 76 | + } |
| 77 | + return root; |
| 78 | + } |
| 79 | + |
| 80 | + vector<string> split(string str, char delimiter) { |
| 81 | + vector<string> result; |
| 82 | + int last = 0; |
| 83 | + for (int i = 0; i <= str.length(); i++) { |
| 84 | + if (str[i] == delimiter || str[i] == '0円') { |
| 85 | + result.push_back(str.substr(last, i - last)); |
| 86 | + last = i + 1; |
| 87 | + } |
| 88 | + } |
| 89 | + return result; |
| 90 | + } |
| 91 | +}; |
| 92 | + |
| 93 | +bool compareTree(TreeNode *a, TreeNode *b) { |
| 94 | + if (a == NULL && b == NULL) return true; |
| 95 | + if (a == NULL || b == NULL) return false; |
| 96 | + |
| 97 | + return (a->val == b->val) |
| 98 | + && compareTree(a->left, b->left) |
| 99 | + && compareTree(a->right, b->right); |
| 100 | +} |
| 101 | + |
| 102 | +// Your Codec object will be instantiated and called as such: |
| 103 | +// Codec codec; |
| 104 | +// codec.deserialize(codec.serialize(root)); |
| 105 | + |
| 106 | +int main() { |
| 107 | + TreeNode *root = new TreeNode(1); |
| 108 | + root->left = new TreeNode(2); |
| 109 | + root->right = new TreeNode(3); |
| 110 | + root->right->left = new TreeNode(4); |
| 111 | + root->right->right = new TreeNode(5); |
| 112 | + |
| 113 | + root->right->left->left = new TreeNode(6); |
| 114 | + root->right->right->right = new TreeNode(7); |
| 115 | + |
| 116 | + // 1 |
| 117 | + // / \ |
| 118 | + // 2 3 |
| 119 | + // / \ |
| 120 | + // 4 5 |
| 121 | + // / \ |
| 122 | + // 6 7 |
| 123 | + // serialization: 1,2,N,3,4,5,L,6,R,7,N,N |
| 124 | + |
| 125 | + Codec codec; |
| 126 | + TreeNode *new_root = codec.deserialize(codec.serialize(root)); |
| 127 | + |
| 128 | + assert(compareTree(root, new_root) == true); |
| 129 | + printf("all tests passed!\n"); |
| 130 | + |
| 131 | + return 0; |
| 132 | +} |
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