Topic

Input stream

Problem

Count words

Read an input text from the console and print the number of words. By word we mean a sequence of characters separated by one or several spaces.

If the input is empty or there are no characters except spaces, print 0.

Hint & Explain

Make sure to follow this order: 1- use reader.readLine() to read the input 2 - use trim() on the input 3- CLOSE THE READER with reader.close() 4- use if statement: 5- if string.isEmpty() then ... 6- else, split("\s+") string into an array => String[] string = input.split("\s+") then print count

Solution

Other solution 1

import java.io.BufferedReader;
import java.io.InputStreamReader;

class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        // start coding here
        String input = reader.readLine().trim();

        reader.close();

        if (input.isEmpty()) {
            System.out.println(0);
        } else {
            String[] array = input.split("\\s+");
            System.out.println(array.length);
        }
    }
}

Other solution 2

import java.io.BufferedReader;
import java.io.InputStreamReader;

class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        // start coding here
        int inputAsInt = reader.read();
        int count = 0;
        final int intSpace = 32;
        final int intDec = 10;
        boolean flag = false;
        while (inputAsInt != -1) {
            if (inputAsInt != intSpace && !flag) {
                count++;
                flag = true;
            } else if (inputAsInt == intSpace) {
                flag = false;
            }
            inputAsInt = reader.read();
            if (inputAsInt == intDec) {
                break;
            }
        }
        System.out.println(count);
        reader.close();
    }
}