Refactor almost everything

Easy/best-time-to-buy-and-sell-stock/solution.cpp

@@ -1,3 +1,5 @@
+#include <vector>
+
 class Solution {
 public:
     int maxProfit(std::vector<int> &prices) {

Easy/contains-duplicate/solution.cpp

@@ -1,3 +1,6 @@
+#include <unordered_set>
+#include <vector>
+
 class Solution {
 public:
     bool containsDuplicate(std::vector<int> &nums) {

Easy/excel-sheet-column-title/Solution.java

@@ -2,8 +2,7 @@ class Solution {
     public String convertToTitle(int num) {
         StringBuilder ttl = new StringBuilder();
 
-        while (num > 0) {
-            --num;
+        while (num-- > 0) {
             char tba = (char)(num % 26 + 65);
             ttl.insert(0, tba);
             num /= 26;

Easy/intersection-of-two-arrays-ii/solution.cpp

@@ -1,3 +1,6 @@
+#include <algorithm>
+#include <vector>
+
 class Solution {
 public:
     /*

Easy/maximum-depth-of-binary-tree/solution.cpp

@@ -10,10 +10,10 @@ struct TreeNode {
 
 class Solution {
 private:
-    void maxDepth(TreeNode *root, int index, int *max) {
+    void maxDepth(TreeNode *root, int index, int &max) {
         if (root == nullptr) {
-            if (index > *max) {
-                *max = index;
+            if (index > max) {
+                max = index;
             }
 
             return;
@@ -26,7 +26,7 @@ class Solution {
 public:
     int maxDepth(TreeNode *root) {
         int max = 0;
-        maxDepth(root, 0, &max);
+        maxDepth(root, 0, max);
 
         return max;
     }

Easy/maximum-number-of-words-you-can-type/Solution.java

@@ -5,15 +5,17 @@ class Solution {
         int ret = 0;
         for (boolean flag = true; words.hasMoreTokens(); flag = true) {
             String word = words.nextToken();
-            for (int i = 0; i < chars.length(); i++)
+            for (int i = 0; i < chars.length(); i++) {
                 if (word.indexOf(chars.charAt(i)) > -1) {
                     flag = false;
                     break;
                 }
+            }
 
-            if (flag)
+            if (flag) {
                 ++ret;
             }
+        }
 
         return ret;
     }

Easy/maximum-subarray/solution.cpp

@@ -1,3 +1,6 @@
+#include <cstdint>
+#include <vector>
+
 class Solution {
 public:
     int maxSubArray(std::vector<int> &nums) {

Easy/merge-sorted-array/solution.cpp

@@ -1,3 +1,6 @@
+#include <algorithm>
+#include <vector>
+
 class Solution {
 public:
     void merge(std::vector<int> &nums1, int m, std::vector<int> &nums2, int n) {

Easy/palindrome-number/solution.c

@@ -1,3 +1,5 @@
+#include <stdbool.h>
+
 bool isPalindrome(long int a) {
     if (a < 0)
         return false;

Easy/pascals-triangle/solution.cpp

@@ -1,3 +1,5 @@
+#include <vector>
+
 class Solution {
 public:
     std::vector<int> getRow(int n) {

Easy/repeated-substring-pattern/solution.cpp

@@ -0,0 +1,27 @@
+#include <string>
+
+class Solution {
+public:
+    bool repeatedSubstringPattern(std::string s) {
+        for (int i = 1; i <= s.size() / 2; ++i) {
+            std::string sl(s.substr(0, i));
+            if (s.size() % i == 0) {
+                bool found = false;
+                for (int j = 1; j < s.size() / i; ++j) {
+                    if (s.find(sl, sl.size() * j) == sl.size() * j) {
+                        found = true;
+                    } else {
+                        found = false;
+                        break;
+                    }
+                }
+
+                if (found) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+};

Easy/reshape-the-matrix/solution.cpp

@@ -1,3 +1,5 @@
+#include <vector>
+
 class Solution {
 public:
     std::vector<std::vector<int>>

Easy/two-sum/solution.cpp

@@ -1,3 +1,6 @@
+#include <unordered_map>
+#include <vector>
+
 class Solution {
 public:
     std::vector<int> twoSum(std::vector<int> &nums, int target) {

Medium/sort-list/solution.c

@@ -1,3 +1,10 @@
+#include <stdlib.h>
+
+struct ListNode {
+    int val;
+    struct ListNode *next;
+};
+
 struct ListNode *merge(struct ListNode *left, struct ListNode *right) {
     if (!left) {
         return right;

Medium/string-to-integer-atoi/solution.cpp

@@ -1,3 +1,5 @@
+#include <string>
+
 class Solution {
 public:
     int myAtoi(std::string s) {

Medium/two-sum-ii-input-array-is-sorted/solution.cpp

@@ -1,3 +1,5 @@
+#include <vector>
+
 class Solution {
 public:
     std::vector<int> twoSum(std::vector<int> &numbers, int target) {
@@ -8,14 +10,15 @@ class Solution {
             j = binarySearch(numbers, 0, numbers.size() - 1, otherhalf);
 
             if (j != -1 && i != j) {
-                if (i < j)
-                    return std::vector{i + 1, j + 1};
-                else
-                    return std::vector{j + 1, i + 1};
+                if (i < j) {
+                    return {i + 1, j + 1};
+                } else {
+                    return {j + 1, i + 1};
+                }
             }
         }
 
-        return std::vector{-1, -1};
+        return {-1, -1};
     }
 
     int binarySearch(std::vector<int> &numbers, int start, int end, int key) {