array_operations.java

import java.util.Arrays;

class num {

    int[] arr;

    public static int missing(int[] ar, int n) {
        int form = (n * (n + 1)) / 2;
        int sum = 0;

        for (int i = 0; i < ar.length; i++) {
            sum = sum + ar[i];
        }

        System.out.println("1. Finding missing number");
        System.out.print("Array:[");
        for (int i = 0; i < ar.length; i++) {
            System.out.print(ar[i] + " ");
        }
        System.out.print("]\n");

        return form - sum;
    }

    public static void sorting(int[] array) {
        System.out.println("\n2. Sorting Array");
        System.out.print("Array:[");
        for (int i = 0; i < array.length; i++) {
            System.out.print(array[i] + " ");
        }
        System.out.print("]\n");

        for (int i = 0; i < array.length - 1; i++) {
            for (int j = 0; j < array.length - 1 - i; j++) {
                if (array[j] > array[j + 1]) {
                    int temp = array[j];
                    array[j] = array[j + 1];
                    array[j + 1] = temp;
                }
            }
        }

        System.out.print("Sorted:[");
        for (int i = 0; i < array.length; i++) {
            System.out.print(array[i] + " ");
        }
        System.out.print("]\n");
    }

    public static void search(int[] array, int n) {
        System.out.println("\n3. Searching");
        System.out.print("Array:[");
        for (int i = 0; i < array.length; i++) {
            System.out.print(array[i] + " ");
        }
        System.out.print("]");
        System.out.print("\nTarget: " + n);

        for (int i = 0; i < array.length; i++) {
            if (array[i] == n) {
                System.out.println("\nTarget found at index: " + i);
            }
        }
    }

    public static void larsm(int[] array) {
        System.out.println("\n4. Finding Largest and Smallest number");
        System.out.print("Array:[");

        for (int i = 0; i < array.length; i++) {
            System.out.print(array[i] + " ");
        }
        System.out.println("]");

        int largest = array[0];
        int smallest = array[0];

        for (int i = 1; i < array.length; i++) {
            if (array[i] > largest) {
                largest = array[i];
            }

            if (array[i] < smallest) {
                smallest = array[i];
            }
        }

        System.out.println("Largest number: " + largest);
        System.out.println("Smallest number: " + smallest);
    }

    public static void findPair(int[] arr, int target) {
        System.out.println("\n5. Finding pair numbers");
        System.out.print("Array:[");
        for (int i = 0; i < arr.length; i++) {
            System.out.print(arr[i] + " ");
        }
        System.out.print("]");

        for (int i = 0; i < arr.length; i++) {
            for (int j = i + 1; j < arr.length; j++) {
                if (arr[i] + arr[j] == target) {
                    System.out.println("\nTarget sum: " + target);
                    System.out.println("Pair found: " + arr[i] + ", " + arr[j]);
                    return;
                }
            }
        }

        System.out.println("\nNo pair found");
    }

    public static int[] deleteele(int[] array, int index) {
        System.out.println("\n6. Deleting element");
        System.out.println("Element at index " + index);
        System.out.println("Array was:");
        System.out.print("[");

        for (int i = 0; i < array.length; i++) {
            System.out.print(array[i] + " ");
        }
        System.out.print("]\n");

        for (int i = index; i < array.length - 1; i++) {
            array[i] = array[i + 1];
        }
        array[array.length - 1] = 0;

        System.out.println("Array is now:");
        System.out.print("[");
        for (int i = 0; i < array.length; i++) {
            System.out.print(array[i] + " ");
        }
        System.out.print("]\n");

        return array;
    }

    public static int[] addele(int[] array, int index, int ele) {
        System.out.println("\n7. Adding element");
        System.out.println("Element: " + ele + " at index " + index);
        System.out.println("Array was:");
        System.out.print("[");

        for (int i = 0; i < array.length; i++) {
            System.out.print(array[i] + " ");
        }
        System.out.print("]\n");

        for (int i = array.length - 2; i >= index; i--) {
            array[i + 1] = array[i];
        }
        array[index] = ele;

        System.out.println("Array is now:");
        System.out.print("[");
        for (int i = 0; i < array.length; i++) {
            System.out.print(array[i] + " ");
        }
        System.out.print("]\n");

        return array;
    }

    public static void mergeArrays(int[] arr1, int[] arr2) {
        System.out.println("\n8. Merging 2 arrays");

        System.out.print("Array 1: [");
        for (int i = 0; i < arr1.length; i++) {
            System.out.print(arr1[i] + " ");
        }
        System.out.print("]\n");

        System.out.print("Array 2: [");
        for (int i = 0; i < arr2.length; i++) {
            System.out.print(arr2[i] + " ");
        }
        System.out.print("]\n");

        int[] merged = new int[arr1.length + arr2.length];
        int index = 0;

        for (int i = 0; i < arr1.length; i++) {
            merged[index++] = arr1[i];
        }

        for (int i = 0; i < arr2.length; i++) {
            merged[index++] = arr2[i];
        }

        System.out.print("Merged array:[");
        for (int i = 0; i < merged.length; i++) {
            System.out.print(merged[i] + " ");
        }
        System.out.print("]");
    }

    public static void main(String[] args) {

        int[] arr1 = {1, 2, 4, 5};
        int[] arr2 = {5, 9, 3, 8, 2};
        int[] arr3 = {10, 46, 28, 46};

        int number = 5;
        int missnum = missing(arr1, number);
        System.out.println("Missing number is: " + missnum);

        sorting(arr2);

        int target = 2;
        search(arr2, target);

        larsm(arr3);

        int[] arr = {2, 7, 11, 15};
        int tar = 9;
        findPair(arr, tar);

        int[] arr4 = {12, 14, 35, 67, 0};
        deleteele(arr4, 3);
        addele(arr4, 2, 8);

        mergeArrays(arr1, arr2);
    }
}