solution

sorting_array/sorting_array.iml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

sorting_array/src/SortingArrayApp.java

@@ -0,0 +1,177 @@
+import java.time.Clock;
+import java.util.Random;
+
+import static java.lang.Math.abs;
+
+public class SortingArrayApp {
+    public static void main(String[] args) {
+        RandomIntArray arr1, arr2, arr3, arr4;
+
+        Clock clock = Clock.systemDefaultZone();
+        long startTime, endTime;
+
+        arr1 = new RandomIntArray(10);
+        arr2 = new RandomIntArray(100000);
+        arr3 = new RandomIntArray(100000);
+        arr4 = new RandomIntArray(100000);
+
+        //  Random array test
+        arr1.printArray("random arr1");
+
+        //  Insert item in array test
+        arr1.insertItem(2, 0);
+        arr1.printArray("arr1: insert item");
+
+        //  Delete item from array test
+        arr1.deleteItem(2);
+        arr1.printArray("arr1: delete item");
+
+        //  Search item in array test
+        int index = arr1.searchItem(4);
+        if (index != -1) {
+            System.out.println("index item is " + index);
+        }
+        else {
+            System.out.println("no value");
+        }
+
+        System.out.println();
+
+        //  Bubble sort test
+        startTime = clock.millis();
+        arr2.bubbleSort();
+        endTime = clock.millis();
+
+        System.out.println("arr2: bubble sort: sorted for " + (endTime - startTime) + " ms");
+
+        //  Insert sort test
+        startTime = clock.millis();
+        arr3.insertSort();
+        endTime = clock.millis();
+
+        System.out.println("arr3: insert sort: sorted for " + (endTime - startTime) + " ms");
+
+        //  Selection sort test
+        startTime = clock.millis();
+        arr4.selectionSort();
+        endTime = clock.millis();
+
+        System.out.println("arr4: selection sort: sorted for " + (endTime - startTime) + " ms");
+    }
+
+
+}
+
+class RandomIntArray {
+    private int[] arr;
+    private int num;
+
+    RandomIntArray(int _num) {
+        num = _num;
+
+        generateRandomArray(num);
+    }
+
+    private void generateRandomArray(int num) {
+        Random random = new Random();
+
+        arr = new int[num];
+        for (int i = 0; i < num; i++) {
+            arr[i] = abs(random.nextInt() % 10);
+        }
+    }
+
+    public void printArray(String label) {
+        System.out.println(label);
+
+        System.out.print("[ ");
+        for (int i : arr) {
+            System.out.print(i + " ");
+        }
+
+        System.out.println("]");
+        System.out.println();
+    }
+
+    public void insertItem(int index, int val) {
+        if (index < 0 || index >= num) {
+            System.out.println("Error: Wrong index");
+            return;
+        }
+
+        for (int i = num-1; i > index; i--) {
+            arr[i] = arr[i-1];
+        }
+        arr[index] = val;
+    }
+
+    public void deleteItem(int index) {
+        if (index < 0 || index >= num) {
+            System.out.println("Error: wrong index");
+            return;
+        }
+
+        for (int i = index; i < num-1; i++) {
+            arr[i] = arr[i+1];
+        }
+        arr[num-1] = 0;
+    }
+
+    public int searchItem(int val) {
+        for (int i = 0; i < num-1; i++) {
+            if (arr[i] == val) {
+                return i;
+            }
+        }
+
+        return -1;
+    }
+
+    public void bubbleSort() {
+        for (int i = 1; i <= num; i++) {
+            for (int j = 0; j < num-i; j++) {
+                if (arr[j] > arr[j+1]) {
+                    changeItems(j, j+1);
+                }
+            }
+        }
+    }
+
+    public void insertSort() {
+        for (int i = 1; i < num; i++) {
+            int temp = arr[i];
+
+            while(i > 0 && arr[i-1] > temp) {
+                arr[i] = arr[i-1];
+                --i;
+            }
+
+            arr[i] = temp;
+        }
+
+    }
+
+    public void selectionSort() {
+        for (int i = 0; i < num; i++) {
+            int min = arr[i];
+            int idx = i;
+
+            for (int j = i+1; j < num; j++) {
+                if (arr[j] < min) {
+                    min = arr[j];
+                    idx = j;
+                }
+            }
+
+            arr[idx] = arr[i];
+            arr[i] = min;
+        }
+    }
+
+    private void changeItems(int idx1, int idx2) {
+        int tmp = arr[idx1];
+
+        arr[idx1] = arr[idx2];
+        arr[idx2] = tmp;
+    }
+}