HackerEarth Questions Asked on 4th June 2015

Q1) Terrible Chandu
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Chandu is a bad student. Once his teacher asked him to print the reverse of a given string. He took three hours to solve it. The teacher got agitated at Chandu and asked you the same question. Can you solve it?

Input:
The first line contains an integer T, denoting the number of test cases.
Each test case contains a string S, comprising of only lower case letters.

Output:
For each test case, print the reverse of the string S.

Constraints:

1 <= T <= 10

1 <= |S| <= 30

Sample Input                 Sample Output

2

ab                              ba

aba                             aba

Answer
----------

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


class TestClass {
         public static void main(String args[] ) throws Exception {
            BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
            String line = br.readLine();
            int N = Integer.parseInt(line);
            for (int i = 0; i < N; i++) {
                String s=br.readLine();
                String r="";
                for(int j=s.length()-1;j>=0;j--){
                   r=r+s.charAt(j);
                }
               System.out.println(r);
           }
       }
}

Q2) Chandu and Consecutive Letters

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Chandu is very fond of strings. (Or so he thinks!) But, he does not like strings which have same consecutive letters. No one has any idea why it is so. He calls these strings as Bad strings. So, Good strings are the strings which do not have same consecutive letters. Now, the problem is quite simple. Given a string S, you need to convert it into a Good String.

You simply need to perform one operation - if there are two same consecutive letters, delete one of them.

Input:
The first line contains an integer T, denoting the number of test cases.
Each test case consists of a string S, which consists of only lower case letters.

Output:
For each test case, print the answer to the given problem.

Constraints:
1 <= T <= 10
1 <= |S| <= 30

Sample Input           Sample Output

3

abb            ab

aaab                     ab

ababa                   ababa

Answer

----------

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


class TestClass {
    public static void main(String args[] ) throws Exception {
       BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String line = br.readLine();
        int N = Integer.parseInt(line);
        for (int i = 0; i < N; i++) {
        String s= br.readLine();
        String r="";
        int x;
        for(int j=0;j<s.length();j=x){
        x=j;
        while(++x<s.length() && s.charAt(x)==s.charAt(j));
        r=r+s.charAt(j);
        }
            System.out.println(r);
        }
    }
}