Added merge sort solution

Author: sunilkumarmaurya786693

leetcode/array/mergeSort.cpp

@@ -0,0 +1,41 @@
+// 88. Merge Sorted Array
+// You are given two integer arrays nums1 and nums2, sorted in non-decreasing order, and two integers m and n, representing the number of elements in nums1 and nums2 respectively.
+// Merge nums1 and nums2 into a single array sorted in non-decreasing order.
+// The final sorted array should not be returned by the function, but instead be stored inside the array nums1. To accommodate this, nums1 has a length of m + n, where the first m elements denote the elements that should be merged, and the last n elements are set to 0 and should be ignored. nums2 has a length of n.
+ 
+// Example 1:
+// Input: nums1 = [1,2,3,0,0,0], m = 3, nums2 = [2,5,6], n = 3
+// Output: [1,2,2,3,5,6]
+// Explanation: The arrays we are merging are [1,2,3] and [2,5,6].
+// The result of the merge is [1,2,2,3,5,6] with the underlined elements coming from nums1.
+ 
+// Example 2:
+// Input: nums1 = [1], m = 1, nums2 = [], n = 0
+// Output: [1]
+// Explanation: The arrays we are merging are [1] and [].
+// The result of the merge is [1].
+ 
+// Example 3:
+// Input: nums1 = [0], m = 0, nums2 = [1], n = 1
+// Output: [1]
+// Explanation: The arrays we are merging are [] and [1].
+// The result of the merge is [1].
+// Note that because m = 0, there are no elements in nums1. The 0 is only there to ensure the merge result can fit in nums1.
+class Solution {
+public:
+   void merge(vector<int>& nums1, int n, vector<int>& nums2, int m) {
+       int p=nums1.size()-1;
+       int i=n-1;
+       int j=m-1;
+       while(i>=0 && j>=0){
+           if(nums2[j]>=nums1[i]){
+               nums1[p--]=nums2[j--];
+           }else{
+               nums1[p--]=nums1[i--];
+           }
+       }
+       while(j>=0){
+           nums1[p--]=nums2[j--];
+       }
+   }
+};