Merge pull request #392 from gauthamlaltv/master

pancake sorting

Author: matthewsamuel95

Sorting/Pancake sorting/pancake.java

@@ -0,0 +1,89 @@
+
+// Java program to 
+// sort array using 
+// pancake sort 
+import java.io.*; 
+  
+class PancakeSort { 
+  
+    /* Reverses arr[0..i] */
+    static void flip(int arr[], int i) 
+    { 
+        int temp, start = 0; 
+        while (start < i) 
+        { 
+            temp = arr[start]; 
+            arr[start] = arr[i]; 
+            arr[i] = temp; 
+            start++; 
+            i--; 
+        } 
+    } 
+  
+    // Returns index of the  
+    // maximum element in  
+    // arr[0..n-1]  
+    static int findMax(int arr[], int n) 
+    { 
+        int mi, i; 
+        for (mi = 0, i = 0; i < n; ++i) 
+            if (arr[i] > arr[mi]) 
+                mi = i; 
+        return mi; 
+    } 
+  
+    // The main function that 
+    // sorts given array using  
+    // flip operations 
+    static int pancakeSort(int arr[], int n) 
+    { 
+        // Start from the complete 
+        // array and one by one 
+        // reduce current size by one 
+        for (int curr_size = n; curr_size > 1; --curr_size) 
+        { 
+            // Find index of the 
+            // maximum element in 
+            // arr[0..curr_size-1] 
+            int mi = findMax(arr, curr_size); 
+  
+            // Move the maximum element 
+            // to end of current array 
+            // if it's not already at  
+            // the end 
+            if (mi != curr_size-1) 
+            { 
+                // To move at the end, 
+                // first move maximum 
+                // number to beginning 
+                flip(arr, mi); 
+  
+                // Now move the maximum  
+                // number to end by 
+                // reversing current array 
+                flip(arr, curr_size-1); 
+            } 
+        } 
+        return 0; 
+    } 
+  
+    /* Utility function to print array arr[] */
+    static void printArray(int arr[], int arr_size) 
+    { 
+        for (int i = 0; i < arr_size; i++) 
+            System.out.print(arr[i] + " "); 
+        System.out.println(""); 
+    } 
+  
+    /* Driver function to check for above functions*/
+    public static void main (String[] args) 
+    { 
+        int arr[] = {23, 10, 20, 11, 12, 6, 7}; 
+        int n = arr.length; 
+          
+        pancakeSort(arr, n); 
+          
+        System.out.println("Sorted Array: "); 
+        printArray(arr, n); 
+    } 
+}