searchAndDestroy.java

import java.io.*;
import java.util.*;
 
 
public class searchAndDestroy {
 
    public static void main(String[] args) throws IOException{

        Scanner input = new Scanner(System.in);
        //Establish array length
        System.out.println("Hey there! Please establish the length of the array");
        int positions = input.nextInt();
 
        
        int[] inputArray = new int[positions];
        Random num = new Random();
 
        for (int i = 0; i < positions; i++) {
            inputArray[i] = num.nextInt(20);
        }
        mergeSort(inputArray);
 
        System.out.println("What number are you looking for?");
        int toFind = input.nextInt();
 
 
        int lapos;
        lapos = linear(inputArray, toFind);
 
        int bazooka;
        bazooka = howMany(inputArray, toFind);
 
        System.out.println("In Linear Search");
 
        System.out.println("Your number first appeared on index ");
        System.out.println(lapos);
 
        System.out.println("Your number was repeated ");
        System.out.println(bazooka + " time(s)");
 
        int bin;
        bin = firstOne(inputArray, toFind);
 
        int ban;
        ban = whereIsIt(inputArray, toFind);
 
        System.out.println("In Binary Search...");
 
        System.out.println("Your number first appears on index ");
        System.out.println(bin);
 
        System.out.println("Your number was repeated ");
        System.out.println(ban + " time(s)");
 
 
 
    }
 
        static void mergeSort(int[] A) {
            if (A.length > 1) {
                int q = A.length/2;
     
                int[] leftArray = Arrays.copyOfRange(A, 0, q);
                int[] rightArray = Arrays.copyOfRange(A,q,A.length);
     
                mergeSort(leftArray);
                mergeSort(rightArray);
     
                merge(A,leftArray,rightArray);
            }
        }
     
            public static void merge(int[] a, int[] l, int[] r) {
                int totElem = l.length + r.length;
                //int[] a = new int[totElem];
                int i,li,ri;
                i = li = ri = 0;
                while ( i < totElem) {
                    if ((li < l.length) && (ri<r.length)) {
                        if (l[li] < r[ri]) {
                            a[i] = l[li];
                            i++;
                            li++;
                        }
                        else {
                            a[i] = r[ri];
                            i++;
                            ri++;
                        }
                    }
                    else {
                        if (li >= l.length) {
                            while (ri < r.length) {
                                a[i] = r[ri];
                                i++;
                                ri++;
                            }
                        }
                        if (ri >= r.length) {
                            while (li < l.length) {
                                a[i] = l[li];
                                li++;
                                i++;
                            }
                        }
                    }
                }
                //return a;
         
            }
 
                public static int linear(int [] inputArray, int toFind) {
             
                    for (int a=0; a<inputArray.length; a++) {
                        if (inputArray[a] == toFind) {
                            return a;
                        }
                        
                    }
                        return -1;
             
                }
             
                    public static int howMany(int [] inputArray, int toFind) {
                 
                        int counT = 0;
                        for (int b=0; b<inputArray.length; b++) {
                            if (inputArray[b] == toFind) {
                                counT = counT + 1;
                            }
                 
                        }
                        return counT;
                    }
                 
                        public static int firstOne(int [] inputArray, int toFind) {
                     
                            int mid;
                            int low = 0;
                            int high = inputArray.length-1;
                     
                            while (low<=high) {
                                mid = (low + high) /2;
                                if (inputArray[mid] > toFind) {
                                    high = mid - 1;
                                } else if (inputArray[mid] < toFind) {
                                    low = mid + 1;
                                } else {
                                    return mid;
                                }
                            }
                            return -1;
                        }
                     
                            public static int whereIsIt(int [] inputArray, int toFind) {
                         
                                int counT = 0;
                                int lol = toFind;
                         
                                for (int k =0; k<inputArray.length; k++) {
                                    if (inputArray[lol] == toFind) {
                                        counT = counT + 1;
                                        lol = lol + 1;
                                    } else {
                                        break;
                                    }
                         
                                }
                                return counT;
                            }
                         
                         
                        }