Notes

import java.util.Scanner;

public class Main
{
public static void main(String[] args) {
//input section
float input1;
char temp;
float output1;
float output2;

Scanner sc =new Scanner(System.in);

System.out.print("enter a value: ");
input1 = sc.nextFloat();

System.out.print("enter the temperature: ");
temp = sc.next().charAt(0);


//Process

if(temp == 'c'){
output1 = ((9/5)*input1)-32;
output2 = input1 + 273.15f;

System.out.println("the convertion of celcius to fahrenheit is: "+output1);
System.out.print("the convertion of celcius to kelvin is: "+output2);

}
else if (temp == 'f'){
//convert the fahrenheit to celcius
output1 = ((input1 - 32) * 5 / 9);
//convert the fahrenheit to kelvin
output2 = ((input1 - 32) * 5 / 9 + 273.15f);

//print the output
System.out.println("the convertion of fahrenheit to celcius is: "+output1);
System.out.println("the convertion of fahrenheit to kelvin is: "+output2);
}
else if (temp == 'k'){
//convert the kelvin to celcius
output1 = (input1 - 273.15f);
//convert the kelvin to fahrenheit
output2 = ((input1 - 273.15f) * 9 / 5 + 32);

//print the output
System.out.println("the convertion of convert the kelvin to celcius is: "+output1);
System.out.println("the convertion of convert the kelvin to fahrenheit is: "+output2);
}
else{
System.out.print("Invalid input of temperature!!");

}
}
}