Merge pull request neetcode-gh#2707 from Piyush-Deshmukh/patch-1

Create 0912-sort-an-array.cpp

cpp/0912-sort-an-array.cpp

@@ -0,0 +1,52 @@
+/*
+ Given an array of integers nums, sort the array in ascending order and return it.
+ Ex. nums = [5,2,3,1] -> [1,2,3,5]
+
+ Use Merge sort to sort the array.
+
+ Time - O(nlogn)
+ Space - O(n)
+*/
+
+class Solution {
+ private:
+ void merge(vector<int> &nums, int low, int mid, int high) {
+ if(low >= high) 
+ return;
+
+ int l = low, r = mid + 1, k = 0, size = high - low + 1;
+ vector<int> sorted(size, 0);
+
+ while (l <= mid and r <= high){
+ if(nums[l] < nums[r])
+ sorted[k++] = nums[l++];
+ else
+ sorted[k++] = nums[r++];
+ }
+
+ while(l <= mid) 
+ sorted[k++] = nums[l++];
+ while(r <= high) 
+ sorted[k++] = nums[r++];
+
+ for(k = 0; k < size; k++)
+ nums[k + low] = sorted[k];
+ }
+
+ void mergeSort(vector<int>& nums, int low, int high){
+ if(low >= high) 
+ return;
+
+ int mid = low + (high - low) / 2;
+
+ mergeSort(nums, low, mid);
+ mergeSort(nums, mid + 1, high);
+ merge(nums, low, mid, high);
+ }
+
+public:
+ vector<int> sortArray(vector<int>& nums) {
+ mergeSort(nums, 0, nums.size()-1);
+ return nums;
+ }
+};