Add sorting algorithms in java (#26)

sorting/README.md

@@ -17,6 +17,12 @@
 2. [Insertion Sort](python/insertion-sort.py)
 2. [Selection Sort](python/selection-sort.py)
 
+### Java
+
+1. [Bubble Sort](java/bubble-sort.java)
+2. [Insertion Sort](java/insertion-sort.java)
+3. [Selection Sort](java/selection-sort.java)
+
 ### JavaScript
 
 1. [Bubble Sort](js/bubble-sort.js)

sorting/java/bubble-sort.java

@@ -0,0 +1,36 @@
+// Java program for implementation of Bubble Sort 
+class BubbleSort 
+{ 
+    void bubbleSort(int arr[]) 
+    { 
+        int n = arr.length; 
+        for (int i = 0; i < n-1; i++) 
+            for (int j = 0; j < n-i-1; j++) 
+                if (arr[j] > arr[j+1]) 
+                { 
+                    // swap arr[j+1] and arr[j] 
+                    int temp = arr[j]; 
+                    arr[j] = arr[j+1]; 
+                    arr[j+1] = temp; 
+                } 
+    } 
+  
+    /* Prints the array */
+    void printArray(int arr[]) 
+    { 
+        int n = arr.length; 
+        for (int i=0; i<n; ++i) 
+            System.out.print(arr[i] + " "); 
+        System.out.println(); 
+    } 
+  
+    // Driver method to test above 
+    public static void main(String args[]) 
+    { 
+        BubbleSort ob = new BubbleSort(); 
+        int arr[] = {64, 34, 25, 12, 22, 11, 90}; 
+        ob.bubbleSort(arr); 
+        System.out.println("Sorted array"); 
+        ob.printArray(arr); 
+    } 
+} 

sorting/java/insertion-sort.java

@@ -0,0 +1,42 @@
+// Java program for implementation of Insertion Sort 
+class InsertionSort { 
+    /*Function to sort array using insertion sort*/
+    void sort(int arr[]) 
+    { 
+        int n = arr.length; 
+        for (int i = 1; i < n; ++i) { 
+            int key = arr[i]; 
+            int 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 array of size n*/
+    static void printArray(int arr[]) 
+    { 
+        int n = arr.length; 
+        for (int i = 0; i < n; ++i) 
+            System.out.print(arr[i] + " "); 
+  
+        System.out.println(); 
+    } 
+  
+    // Driver method 
+    public static void main(String args[]) 
+    { 
+        int arr[] = { 12, 11, 13, 5, 6 }; 
+  
+        InsertionSort ob = new InsertionSort(); 
+        ob.sort(arr); 
+  
+        printArray(arr); 
+    } 
+} 

sorting/java/selection-sort.java

@@ -0,0 +1,43 @@
+// Java program for implementation of Selection Sort 
+class SelectionSort 
+{ 
+    void sort(int arr[]) 
+    { 
+        int n = arr.length; 
+  
+        // One by one move boundary of unsorted subarray 
+        for (int i = 0; i < n-1; i++) 
+        { 
+            // Find the minimum element in unsorted array 
+            int min_idx = i; 
+            for (int j = i+1; j < n; j++) 
+                if (arr[j] < arr[min_idx]) 
+                    min_idx = j; 
+  
+            // Swap the found minimum element with the first 
+            // element 
+            int temp = arr[min_idx]; 
+            arr[min_idx] = arr[i]; 
+            arr[i] = temp; 
+        } 
+    } 
+  
+    // Prints the array 
+    void printArray(int arr[]) 
+    { 
+        int n = arr.length; 
+        for (int i=0; i<n; ++i) 
+            System.out.print(arr[i]+" "); 
+        System.out.println(); 
+    } 
+  
+    // Driver code to test above 
+    public static void main(String args[]) 
+    { 
+        SelectionSort ob = new SelectionSort(); 
+        int arr[] = {64,25,12,22,11}; 
+        ob.sort(arr); 
+        System.out.println("Sorted array"); 
+        ob.printArray(arr); 
+    } 
+}