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Java Array Exercises: Find common elements from three sorted arrays

Java Array: Exercise-25 with Solution

Write a Java program to find common elements from three sorted (in non-decreasing order) arrays.

Pictorial Presentation:

Java Array Exercises: Find common elements from three sorted arrays

Sample Solution:

Java Code:

import java.util.*;
public class Exercise25 {
public static void main(String[] args) {
	ArrayList<Integer> common = new ArrayList<Integer>();
   int array1[] = {2, 4, 8};
   int array2[] = {2, 3, 4, 8, 10, 16};
   int array3[] = {4, 8, 14, 40};
	int x = 0, y = 0, z = 0;
	while (x < array1.length && y < array2.length && z < array3.length){
		if (array1[x] == array2[y] && array2[y] == array3[z]){
			common.add(array1[x]);
			x++;
			y++;
			z++;
		}
		else if (array1[x] < array2[y])
			x++;
		else if (array2[y] < array3[z])
			y++;
		else
			z++;
	}
	System.out.println("Common elements from three sorted (in non-decreasing order ) arrays: ");
System.out.println(common);
}
}

Sample Data: array1 = 2, 4, 8
array2 = 2, 3, 4, 8, 10, 16
array3 = 4, 8, 14, 40

Sample Output:

                                                                              
Common elements from three sorted (in non-decreasing order ) arrays:   
[4, 8]

Flowchart:

Flowchart: Java exercises: Find common elements from three sorted arrays

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Java Code Editor:

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Previous: Write a Java program to find a missing number in an array.
Next: Write a Java program to move all 0's to the end of an array. Maintain the relative order of the other (non-zero) array elements.

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Java: Tips of the Day

Different between parseInt() and valueOf() in java?

Well, the API for Integer.valueOf(String) does indeed say that the String is interpreted exactly as if it were given to Integer.parseInt(String). However, valueOf(String) returns a new Integer() object whereas parseInt(String) returns a primitive int.

If you want to enjoy the potential caching benefits of Integer.valueOf(int), you could also use this eyesore:

Integer k = Integer.valueOf(Integer.parseInt("123"))

Now, if what you want is the object and not the primitive, then using valueOf(String) may be more attractive than making a new object out of parseInt(String) because the former is consistently present across Integer, Long, Double, etc.

Ref: https://bit.ly/3vRuIPY