Lab2_20170306

import java.io.*;
public class L2 {

	public static void main(String[] args) throws IOException {
		//Exercise 1
		System.out.print("Enter an integer beteen 0 and 1000:");
		BufferedReader buf = new BufferedReader(new InputStreamReader(System.in));
		String num = buf.readLine();
		String[] digit = num.split("");
		
		int digits[] = new int[digit.length];
		for(int i=0;i<digit.length;i++)
		{
			digits[i] = Integer.parseInt(digit[i]);
		}
		
		int total = 0;
		for(int i=0;i<digit.length;i++)
		{
			total = total + digits[i];
		}
		System.out.print("The sum of all digits in "+ num + " is " + total +"\n");
		
		//Exercicse 2
		System.out.print("Enter an integer beteen 0 and 1000:");
		BufferedReader buf2 = new BufferedReader(new InputStreamReader(System.in));
		String num2 = buf2.readLine();
		String[] digit2 = num2.split("");
		
		int digits2[] = new int[digit2.length];
		for(int i=0;i<digit2.length;i++)
		{
			digits2[i] = Integer.parseInt(digit2[i]);
		}
		
		int total2 = 1;
		for(int i=0;i<digit2.length;i++)
		{
			if(digits2[i] != 0)
			{
				total2 = total2 * digits2[i];
			}
		}
		System.out.print("The multiplication of all digits in "+ num2 + " is " + total2 +"\n");
		
		//Exercise 3
		System.out.print("Enter the radius of a circle:");
		BufferedReader buf3 = new BufferedReader(new InputStreamReader(System.in));
		String r = buf3.readLine();
		int radius = Integer.parseInt(r);
		System.out.print("The area of the circle is:" + radius*radius * Math.PI +"\n");
		System.out.print("The circumference of the circle is:" + 2*radius * Math.PI +"\n");
		
		//Exercise 4
		System.out.print("Enter the amount of water in kilograms:");
		BufferedReader buf4 = new BufferedReader(new InputStreamReader(System.in));
		String num4 = buf4.readLine();
		System.out.print("Enter the initial temperature:");
		BufferedReader buf5 = new BufferedReader(new InputStreamReader(System.in));
		String num5 = buf5.readLine();
		System.out.print("Enter the final temperature:");
		BufferedReader buf6 = new BufferedReader(new InputStreamReader(System.in));
		String num6 = buf6.readLine();
		double kilo = Double.parseDouble(num4);
		double init = Double.parseDouble(num5);
		double finl = Double.parseDouble(num6);
		System.out.print("The energy needed is " + kilo*(finl-init) *4184);
	}

}