3) Write a program that populates a java.util.Arraylist variable with 10 random

Question

3) Write a program that populates a java.util.Arraylist variable with 10 random integers in [1, 20), asks the user to provide a value, and counts how many numbers are equal to the value entered by the user. 4) Write a program that populates a java.util.Arraylist variable with 20 random integers in [1, 100] and prints the location of the smallest (the minimum) integer. Note: Exercises 3 and 4 are similar to Exercises 1 and 2 in Week 8 lab, respectively. On Week 8 you used an array to store the values and this week you will be using a java.util.Arraylist variable.

Explanation / Answer

Hi I have written two programs. Please check the code and test it once and let me know any querries.

CountProgram.java

import java.util.ArrayList;

import java.util.Random;

import java.util.Scanner;

public class CountProgram {

public static int randInt(int min, int max) {

Random rand = new Random();

int randomNum = rand.nextInt((max - min) + 1) + min;

return randomNum;

}

public static void main(String[] args) {

// TODO Auto-generated method stub

Scanner sc = new Scanner(System.in);

ArrayList<Integer> randomList = new ArrayList<Integer>();

for(int i=0;i<10;i++){

randomList.add(randInt(1,20));

}

System.out.println("Enter a Number");

int num = sc.nextInt();

int count = 0;

for(int a:randomList){

if(a==num){

count++;

}

}

System.out.println("Count of numbers equal is:"+count);

}

}

Output:

Enter a Number
5
Count of numbers equal is:1

LocationProgram.java

import java.util.ArrayList;

import java.util.Collections;

import java.util.Random;

import java.util.Scanner;

public class LocationProgram {

public static int randInt(int min, int max) {

Random rand = new Random();

int randomNum = rand.nextInt((max - min) + 1) + min;

return randomNum;

}

public static void main(String[] args) {

// TODO Auto-generated method stub

Scanner sc = new Scanner(System.in);

ArrayList<Integer> randomList = new ArrayList<Integer>();

for(int i=0;i<20;i++){

randomList.add(randInt(1,100));

}

int minIndex = randomList.indexOf(Collections.min(randomList));

System.out.println("Minimum Index is:"+minIndex+" Minimum Value:"+randomList.get(minIndex));

System.out.println("Minimum Index with traversing list is:"+getIndexOfMin(randomList)+" Minimum Value:"+randomList.get(getIndexOfMin(randomList)));

}

public static int getIndexOfMin(ArrayList<Integer> data) {

int min = Integer.MAX_VALUE;

int index = -1;

for (int i = 0; i < data.size(); i++) {

int f = data.get(i);

if (Integer.compare(f, min) < 0) {

min = f;

index = i;

}

}

return index;

}

}

Output:

Minimum Index is:11 Minimum Value:1
Minimum Index with traversing list is:11 Minimum Value:1

For second i have written two types techniques for finding the minimum value.

Please test it and let me know any querries. Thank you. All the best.

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