AVERAGE LEVEL JAVA PROGRAMS

PROGRAM TO ADD THE REVERSED NUMBER OF THE DATA:

STATEMENT:

A pair of numbers (X and Y) will be passed as input. The program must reverse the numbers and find the sum S. Then the sum S must be reversed and printed as output.

- If any leading zeroes are obtained while reversing any of the numerical values they should be discarded.


PROGRAM:

import java.util.*;

public class Hello {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int y = sc.nextInt();
        int sum = reverse(x) + reverse(y);
        System.out.println(reverse(sum));

    }

    private static int reverse(int x) {
        StringBuilder sb = new StringBuilder(String.valueOf(x));
        return Integer.parseInt(sb.reverse().toString());
    }
}

Input:
305
794

Output:
1

Explanation:
305 and 794 when reversed are 503 and 497.
503+497 = 1000.
1000 when reversed is 1 which is printed as output.


PROGRAM TO PRINT THE NUMBER OF STEPS NEEDED TO FILL A CAN WITH WATER;

STATEMENT:

Two cans are with capacity X and Y liters. The program must determine the number of steps required to obtain exactly Z litres of liquid in one of the cans.
At the beginning both cans are empty. The following operations are counted as "steps".

- emptying a vessel,
- filling a vessel,
- pouring liquid from larger can to the smaller, without spilling, until one of the cans is either full or empty.

If it is not possible to obtain Z liters exactly then the output must be -1.

PROGRAM:

import java.util.*;

public class Hello {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int y = sc.nextInt();
        int z = sc.nextInt();
        //Larger can is made as x
        if (x < y) {
            int temp = y;
            y = x;
            x = temp;
        }
        int fillCount = -1, currCount = 1; //currCount is made 1 to fill x
        boolean isSmallerCanFilled = false; //y will be the smaller can

        for (; x >= z; x -= y) {
            if (x == z) {
                fillCount = currCount;
                break;
            } else {
                if (isSmallerCanFilled) {
                    //We need to empty smaller can in step 1 and fill from larger can as step 2
                    currCount += 2;
                } else {
                    isSmallerCanFilled = true;
                    //Only filling from larger to smaller can as step 1. This happens only one time.
                    currCount += 1;
                }

            }
        }
        System.out.print(fillCount);
    }
}

Input:
5
2
3

Output:
2

Explanation:
Here X=5, Y=2
Step 1: Pour 5 liters of liquid into 5 liter can
Step 2: Pour 2 liters from 5 liter can into 2 liter can.
Now the 5 liter can will have 3 liters which is Z. Hence 2 steps are required.