added insertion sort

insert.c

@@ -0,0 +1,42 @@
+#include <math.h> 
+#include <stdio.h> 
+
+/* Function to sort an array using insertion sort*/
+void insertionSort(int arr[], int n) 
+{ 
+    int i, key, j; 
+    for (i = 1; i < n; i++) { 
+        key = arr[i]; 
+        j = i - 1; 
+
+        /* Move elements of arr[0..i-1], that are 
+          greater than key, to one position ahead 
+          of their current position */
+        while (j >= 0 && arr[j] > key) { 
+            arr[j + 1] = arr[j]; 
+            j = j - 1; 
+        } 
+        arr[j + 1] = key; 
+    } 
+} 
+
+// A utility function to print an array of size n 
+void printArray(int arr[], int n) 
+{ 
+    int i; 
+    for (i = 0; i < n; i++) 
+        printf("%d ", arr[i]); 
+    printf("\n"); 
+} 
+
+/* Driver program to test insertion sort */
+int main() 
+{ 
+    int arr[] = { 12, 11, 13, 5, 6 }; 
+    int n = sizeof(arr) / sizeof(arr[0]); 
+
+    insertionSort(arr, n); 
+    printArray(arr, n); 
+
+    return 0; 
+}