3

Author: hitzzc

README.md

@@ -261,6 +261,9 @@ Golang solution for leetcode. For each problem, there is a simple *_test.go to t
 #### [376. Wiggle Subsequence](https://github.com/hitzzc/go-leetcode/tree/master/wiggle_subsequence)
 #### [377. Combination Sum IV](https://github.com/hitzzc/go-leetcode/tree/master/combination_sum_IV)
 #### [378. Kth Smallest Element in a Sorted Matrix](https://github.com/hitzzc/go-leetcode/tree/master/kth_smallest_element_in_a_sorted_matrix)
+#### [383. Ransom Note](https://github.com/hitzzc/go-leetcode/tree/master/ransom_note)
+#### [384. Shuffle an Array](https://github.com/hitzzc/go-leetcode/tree/master/shuffle_an_array)
+#### [386. Lexicographical Numbers](https://github.com/hitzzc/go-leetcode/tree/master/lexicographical_numbers)
 
 
 

lexicographical_numbers/lexicographical_numbers.cpp

@@ -0,0 +1,21 @@
+class Solution {
+public:
+    vector<int> lexicalOrder(int n) {
+        vector<int> result;
+        for (int i = 1; i <= n && i <= 9; ++i) {
+        	result.push_back(i);
+        	helper(i, n, result);
+        }
+        return result;
+    }
+
+    void helper(int num, int n, vector<int>& result) {
+    	for (int i = 0; i <= 9; ++i) {
+    		int tmp = num*10 + i;
+    		if (tmp > n) break;
+    		result.push_back(tmp);
+    		helper(tmp, n, result);
+    	}
+    	return;
+    }
+};

ransom_note/ransom_note.cpp

@@ -0,0 +1,14 @@
+class Solution {
+public:
+    bool canConstruct(string ransomNote, string magazine) {
+        vector<int> count(26, 0);
+        for (auto& ch: magazine) {
+        	++count[ch-'a'];
+        }
+        for (auto& ch: ransomNote) {
+        	if (count[ch-'a'] <= 0) return false;
+        	--count[ch-'a'];
+        }
+        return true;
+    }
+};

shuffle_an_array/shuffle_an_array.cpp

@@ -0,0 +1,30 @@
+class Solution {
+public:
+    Solution(vector<int> nums): nums(nums), current(nums) {
+        srand(time(NULL));
+    }
+    
+    /** Resets the array to its original configuration and return it. */
+    vector<int> reset() {
+        return current = nums;
+    }
+    
+    /** Returns a random shuffling of the array. */
+    vector<int> shuffle() {
+    	int i = current.size();
+    	while (--i > 0) {
+    		int j = rand() % (i+1);
+    		swap(current[i], current[j]);
+    	}
+    	return current;
+    }
+private:
+    vector<int> nums, current;
+};
+
+/**
+ * Your Solution object will be instantiated and called as such:
+ * Solution obj = new Solution(nums);
+ * vector<int> param_1 = obj.reset();
+ * vector<int> param_2 = obj.shuffle();
+ */