Selection Sort, Merge Sort and Insertion Sort in Sort class also with corresponding Tests

src/main/java/sortalgorithms/Sort.java

@@ -6,23 +6,23 @@ public class Sort {
     private int[] inputArray;
 
 
-    public int[] bubbleSort(int[] inputArray){
+    public int[] bubbleSort(int[] inputArray) {
 
-        int size=inputArray.length-1;
-        int temp=-1;
+        int size = inputArray.length - 1;
+        int temp = -1;
 
-        if(size==1)
+        if (size == 1)
             return inputArray;
 
-        for(int i=0;i<=size;i++){
+        for (int i = 0; i <= size; i++) {
 
-            for(int j=0;j<size-i;j++){
+            for (int j = 0; j < size - i; j++) {
 
-                if(inputArray[j]>inputArray[j+1]){
+                if (inputArray[j] > inputArray[j + 1]) {
 
-                    temp=inputArray[j+1];
-                    inputArray[j+1]=inputArray[j];
-                    inputArray[j]=temp;
+                    temp = inputArray[j + 1];
+                    inputArray[j + 1] = inputArray[j];
+                    inputArray[j] = temp;
 
 
                 }
@@ -35,6 +35,128 @@ public int[] bubbleSort(int[] inputArray){
 
     }
 
+
+    public int[] selectionSort(int[] inputArray) {
+
+        int size = inputArray.length - 1;
+
+        if (size == 1)
+            return inputArray;
+
+        for (int i = 0; i < size; i++) {
+            int index = i;
+            for (int j = i + 1; j < size; j++) {
+                if (inputArray[j] < inputArray[index]) {
+                    index = j;//searching for lowest index
+                }
+            }
+            int smallerNumber = inputArray[index];
+            inputArray[index] = inputArray[i];
+            inputArray[i] = smallerNumber;
+        }
+        return inputArray;
+
+    }
+
+    public int[] insertionSort(int[] inputArray) {
+
+        int size = inputArray.length - 1;
+        if (size == 1)
+            return inputArray;
+        for (int i = 1; i < size; ++i) {
+            int key = inputArray[i];
+            int j = i - 1;
+
+
+            while (j >= 0 && inputArray[j] > key) {
+                inputArray[j + 1] = inputArray[j];
+                j = j - 1;
+            }
+            inputArray[j + 1] = key;
+        }
+        return inputArray;
+
+    }
+
+
+
+
+    // Main function that sorts inputArray[l..r] using
+    // merge()
+    public int[] mergeSort(int[] inputArray, int l, int r) {
+        if (l < r) {
+            // Find the middle point
+            int m = (l + r) / 2;
+
+            // Sort first and second halves
+            mergeSort(inputArray, l, m);
+            mergeSort(inputArray, m + 1, r);
+
+            // Merge the sorted halves
+            merge(inputArray, l, m, r);
+        }
+                return inputArray;
+    }
+
+
+    /* Java program for Merge Sort */
+    // Merges two subarrays of inputArray[];
+    // First subarray is inputArray[l..m]
+    // Second subarray is inputArray[m+1..r]
+
+    public void merge(int[] inputArray, int l, int m, int r) {
+        // Find sizes of two subarrays to be merged
+        int n1 = m - l + 1;
+        int n2 = r - m;
+
+        /* Create temp arrays */
+        int L[] = new int[n1];
+        int R[] = new int[n2];
+
+        /*Copy data to temp arrays*/
+        for (int i = 0; i < n1; ++i)
+            L[i] = inputArray[l + i];
+        for (int j = 0; j < n2; ++j)
+            R[j] = inputArray[m + 1 + j];
+
+
+        /* Merge the temp arrays */
+
+        // Initial indexes of first and second subarrays
+        int i = 0, j = 0;
+
+        // Initial index of merged subarray array
+        int k = l;
+        while (i < n1 && j < n2) {
+            if (L[i] <= R[j]) {
+                inputArray[k] = L[i];
+                i++;
+            } else {
+                inputArray[k] = R[j];
+                j++;
+            }
+            k++;
+        }
+
+        /* Copy remaining elements of L[] if any */
+        while (i < n1) {
+            inputArray[k] = L[i];
+            i++;
+            k++;
+        }
+
+        /* Copy remaining elements of R[] if any */
+        while (j < n2) {
+            inputArray[k] = R[j];
+            j++;
+            k++;
+        }
+
+    }
+
+
+
+
     public Sort(int[] inputArray) {
         this.inputArray = inputArray;
     }
@@ -46,4 +168,6 @@ public int[] getInputArray() {
     public void setInputArray(int[] inputArray) {
         this.inputArray = inputArray;
     }
+
+
 }

src/main/java/sortalgorithms/Test.java

@@ -11,7 +11,9 @@ public static void main(String[] args) {
 
         Sort doSort=new Sort(inputs);
         System.out.println(Arrays.toString(doSort.bubbleSort(inputs)));
-
+        System.out.println(Arrays.toString(doSort.selectionSort(inputs)));
+        System.out.println(Arrays.toString(doSort.mergeSort(inputs)));
+        System.out.println(Arrays.toString(doSort.insertionSort(inputs)));