JavaOperation

Q1 - Write a program to add 8 to the number x and then divide it by 3. Now, the modulus of the quotient
is taken with 5 and then multiply the resultant value by 5. Display the final result.
Input: 2345
Output: 20
Code:
import java.util.Scanner;
public class Main {

Assignment Solutions

Cracking the Coding Interview in Java - Foundation

Input: 5 10
Output: 10 5
Q2 - Swap two numbers without the use of third variable.

import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner scn = new Scanner(System.in);
System.out.println("Enter 1st number");
int x = scn.nextInt();
System.out.println("Enter 2nd number");
int y = scn.nextInt();
x = x + y;
y = x - y;
x = x - y;
System.out.println(x);
System.out.println(y);
}
}
Code:

Assignment Solutions

Cracking the Coding Interview in Java - Foundation

Q3 - Write a program to calculate the sum of the digits of a 3-digit number.
Input: 132
Output: 6
Code:
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner scn = new Scanner(System.in);
int x = scn.nextInt();
int sum = 0;
while(x > 0){
sum += x % 10;
x /= 10;
}
System.out.println(sum);
}
}

Assignment Solutions

Cracking the Coding Interview in Java - Foundation

Code:
i) both the conditions 'a < 50' and 'a < b' are true.
ii) at least one of the conditions 'a < 50' or 'a < b' is true.
Q4 - Assign values of variables 'a' and 'b' as 55 and 70 respectively and then check if:

public class Main {
public static void main(String[] args) {

int a = 55;
int b = 70;
System.out.print(a < 50 && a < b);

}
}

public class Main {
public static void main(String[] args) {

int a = 55;
int b = 70;
System.out.print(a < 50 || a < b);

}
}

Assignment Solutions

Cracking the Coding Interview in Java - Foundation

Code:
Q5 - Find the total number of bits needed to be flipped to convert x to y.
Input: 65 80
Output: 2

counting set bits
The idea is to take XOR of the given two integers. After calculating the XOR, the problem will reduce to
counting set bits in the XOR output using Brian Kernighan algorithm.

import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner scn = new Scanner(System.in);
int x = scn.nextInt();
int y = scn.nextInt();
int n = x ^ y;
int count = 0;
while (n != 0){
n = n & (n - 1);
count++;
}
System.out.print(count);
}
}