chore(CPlusPlus): add merge two sorted in array (#612)

Co-authored-by: Ming Tsai <37890026+ming-tsai@users.noreply.github.com>

algorithms/CPlusPlus/Arrays/merge-two-sorted-array.cpp

@@ -0,0 +1,77 @@
+//c++ program to merge two sorted array  without using  extra space.
+//sample: input
+//arr1[]= 1 4 7 8 10;
+//arr2[]=2 3 9;
+//sample output:
+//arr1[]={1,2,3,4,7}
+//arr2[]={8,9,10}
+//Time complexity: O(n1*m1) ,n1 is for linear traversal and m1 is for reordering.
+//space complexity:O(1)
+#include<bits/stdc++.h>
+using namespace std;
+void printArray(int arr[], int n)
+{
+    for (int i = 0; i < n; i++) 
+	{
+        cout << arr[i] << " ";
+    }
+     
+    cout << endl;
+}
+void merge_array(int arr1[],int arr2[],int n1,int n2)
+{
+	for(int i=0;i<n1;i++)
+	{
+		// we will check the condition if the element of array1 is greater than array2, if true ,simply swap them.
+		if(arr1[i]>arr2[0])
+		{
+			int temp=arr1[i];       /* logic for swapping the elements */ 
+			arr1[i]=arr2[0];
+			arr2[0]=temp;
+		/*	swap(arr1[i],arr2[0]); this is stl function to swap the element*/
+		// after swapping the array element we need to sort the element of second array because array is sorted.
+			int key,j;
+			for(int i=1;i<n2;i++)
+			{
+				key=arr2[i];
+				j=i-1;
+		     while(j>=0 && arr2[j]>key)
+		     {
+		     	arr2[j+1]=arr2[j];
+		     	j=j-1;
+			 }
+				
+			arr2[j+1]=key;
+			}
+		
+		}
+	}
+}
+
+int main()
+{  
+    //declaring a array1 and array2, 
+	int arr1[100],arr2[100];
+	int n1,n2,i;
+	cout<<"Enter the element number of  you want in array 1 and array2"<<" ";
+	cin>>n1>>n2;
+	//taking user input for the array1 element and array2 element.
+	cout<<"enter the element of array1"<<" ";
+	for(i=0;i<n1;i++)
+	{
+		cin>>arr1[i];
+	}
+	cout<<"enter the element of array2"<<" ";
+	for(i=0;i<n2;i++)
+	{
+		cin>>arr2[i];
+	}
+	//calling the merge array function.
+	merge_array(arr1,arr2,n1,n2);
+	//for printing the final array element.
+	cout << "arr1: "; printArray(arr1, n1);
+    cout << "arr2: "; printArray(arr2, n2);
+    return 0;
+	
+}
+

algorithms/CPlusPlus/README.md

@@ -25,6 +25,7 @@
 - [Index of Smallest element of Array](Arrays/index-of-smallest-element-of-array.cpp)
 - [Move Zeros to End of The Array](Arrays/move-zeros-to-end-of-array.cpp)
 - [Kadane's Algorithm](Arrays/Kadane's-Algorithm.cpp)
+- [Merge two sorted array without using extraspace](Arrays/merge-two-sorted-array.cpp)
 - [All unique triplet that sum up to given value](Arrays/three-sum.cpp)
 
 ## Dynamic-Programming