2 problems

Author: hitzzc

README.md

@@ -213,6 +213,8 @@ Golang solution for leetcode. For each problem, there is a simple *_test.go to t
 #### [290. Word Pattern](https://github.com/hitzzc/go-leetcode/tree/master/word_pattern)
 #### [292. Nim Game](https://github.com/hitzzc/go-leetcode/tree/master/nim_game)
 #### [295. Find Median from Data Stream](https://github.com/hitzzc/go-leetcode/tree/master/find_median_from_data_stream)
+#### [297. Serialize and Deserialize Binary Tree](https://github.com/hitzzc/go-leetcode/tree/master/serialize_and_deserialize_binary_tree)
+#### [299. Bulls and Cows](https://github.com/hitzzc/go-leetcode/tree/master/bulls_and_cows)
 
 
 

bulls_and_cows/bulls_and_cows.cpp

@@ -0,0 +1,28 @@
+#include <string>
+using namespace std;
+
+class Solution {
+public:
+    string getHint(string secret, string guess) {
+        int secret_array[10] = {0};
+        int bull = 0;
+        for (int i = 0; i < secret.size(); ++i) {
+        	if (secret[i] == guess[i]) {
+        		++bull;
+        		continue;
+        	}
+        	++secret_array[secret[i]-'0'];
+        }
+        int cow = 0;
+        for (int i = 0; i < guess.size(); ++i) {
+        	if (secret[i] == guess[i]) {
+        		continue;
+        	}
+        	if (secret_array[guess[i]-'0'] !=0 ){
+        		++cow;
+        		--secret_array[guess[i]-'0'];
+        	}
+        }
+        return to_string(bull) + "A" + to_string(cow) + "B";
+    }
+};

serialize_and_deserialize_binary_tree/serialize_and_deserialize_binary_tree.cpp

@@ -0,0 +1,44 @@
+#include <string>
+using namespace std;
+
+struct TreeNode {
+	int val;
+	TreeNode *left;
+	TreeNode *right;
+	TreeNode(int x) : val(x), left(NULL), right(NULL) {}
+};
+
+class Codec {
+public:
+    string serialize(TreeNode* root) {
+        if (root == NULL) {
+        	return "null";
+        }
+        string ret = to_string(root->val);
+        ret += "," + serialize(root->left);
+        ret += "," + serialize(root->right);
+        return ret; 
+    }
+
+    TreeNode* deserialize(string data) {
+    	int idx = 0;
+    	return helper(data, idx);
+    }
+
+    TreeNode* helper(string& data, int& idx) {
+    	int start = idx;
+    	for (; idx < data.size(); ++idx) {
+    		if (data[idx] == ',') {
+    			break;
+    		}
+    	}
+    	string sub = data.substr(start, idx-start);
+    	++idx;
+    	if (sub == "null") return NULL;
+    	TreeNode* node = new TreeNode(stoi(sub));
+    	if (idx == data.size()) return node;
+    	node->left = helper(data, idx);
+    	node->right = helper(data, idx);
+    	return node;
+    }
+};