Insertion sort

Author: pingalacharya

SortingAlgorithms/insertionsort.cpp

@@ -0,0 +1,61 @@
+/*Enter number of elements: 5
+
+Enter 5 elements
+4 3 5 1 2
+
+Original List
+4 3 5 1 2
+Sorted List in Ascending Order
+1 2 3 4 5
+Sorted List in Descending Order
+5 4 3 2 1 */
+
+#include<iostream>  
+using namespace std;  
+int main ()  
+{    
+	int n;
+	cout << "Enter number of elements: ";
+	cin >> n;
+    int *arr = new int [n];
+    cout<<"\nEnter "<< n <<" elements\n";
+    // add elemnts
+    for(int i = 0; i < n; i++)
+    	cin >> arr[i];
+    //print original array
+    cout<<"\nOriginal List\n";
+    for(int i=0;i<n;i++)  
+        cout <<arr[i]<<" ";  
+    for(int i=1; i<n; i++)   
+    {  
+        int temp = arr[i];  //store the key
+        int j= i-1; 
+        // search a lower for insertion
+        while(j>=0 && temp <= arr[j])  
+        {  
+            arr[j+1] = arr[j];   
+            j = j-1;  
+        }  
+        arr[j+1] = temp;  
+    }  
+    cout<<"\nSorted List in Ascending Order\n";
+    // print the new list
+     for(int i=0;i<n;i++)  
+        cout <<arr[i]<<" ";
+     for(int i=1; i<n; i++)   
+    {  
+        int temp = arr[i];  
+        int j= i-1;  
+        //do similarly as above only now search             for greater number
+        while(j>=0 && temp >= arr[j])  
+        {  
+            arr[j+1] = arr[j];   
+            j = j-1;  
+        }  
+        arr[j+1] = temp;  
+    }  
+    // print the new list
+    cout<<"\nSorted List in Descending Order\n";
+    for(int i=0;i<n;i++)  
+        cout <<arr[i]<<" ";
+}