Ornek Soru

1. You are given an array and you need to find number of tripets of indices  such that the elements at those indices are in geometric progression for a given common ratio  and .

For example, . If , we have  and  at indices  and .

Function Description
Complete the countTriplets function in the editor below. It should return the number of triplets forming a geometric progression for a given  as an integer. countTriplets has the following parameter(s):
* arr: an array of integers
* r: an integer, the common ratio

Input Format
The first line contains two space-separated integers  and , the size of  and the common ratio.

The next line contains  space-seperated integers .

Constraints
* 
* 
* 

Output Format
Return the count of triplets that form a geometric progression.

Sample Input 0

4 2
1 2 2 4

Sample Output 0

2

Explanation 0
There are  triplets in satisfying our criteria, whose indices are  and 

Sample Input 1

6 3
1 3 9 9 27 81

Sample Output 1

6

Explanation 1
The triplets satisfying are index , , , ,  and .

Solution

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class Soru03 {

  // Complete the countTriplets function below.
    static long countTriplets(List<Long> arr, long r) {

     Map<Long, Long> potential = new HashMap<>();
        Map<Long, Long> counter = new HashMap<>();
        long count = 0;
        for (int i = 0; i < arr.size(); i++) {
            long a = arr.get(i);
            long key = a / r;
            
            if (counter.containsKey(key) && a % r == 0) {
                count += counter.get(key);
            }
            
            if (potential.containsKey(key) && a % r == 0) {
                long c = potential.get(key);
                counter.put(a, counter.getOrDefault(a, 0L) + c);
            }
            
            potential.put(a, potential.getOrDefault(a, 0L) + 1); // Every number can be the start of a triplet.
        }
        return count;
    }

    public static void main(String[] args) throws IOException {
       
        long r = 3;
        List<Long> arr = new ArrayList<Long>();
        arr.add((long) 1);
        arr.add((long) 3);
        arr.add((long) 9);
        arr.add((long) 9);
        arr.add((long) 27);
        arr.add((long) 81);
        long ans = countTriplets(arr, r);
        
        System.out.println(ans);
       
    }
}

2. Harold is a kidnapper who wrote a ransom note, but now he is worried it will be traced back to him through his handwriting. He found a magazine and wants to know if he can cut out whole words from it and use them to create an untraceable replica of his ransom note. The words in his note are case-sensitive and he must use only whole words available in the magazine. He cannot use substrings or concatenation to create the words he needs.

Given the words in the magazine and the words in the ransom note, print Yes if he can replicate his ransom note exactly using whole words from the magazine; otherwise, print No.

For example, the note is "Attack at dawn". The magazine contains only "attack at dawn". The magazine has all the right words, but there's a case mismatch. The answer is .

Function Description

Complete the checkMagazine function in the editor below. It must print  if the note can be formed using the magazine, or .

checkMagazine has the following parameters:

• magazine: an array of strings, each a word in the magazine
• note: an array of strings, each a word in the ransom note

Input Format

The first line contains two space-separated integers,  and , the numbers of words in the  and the ..
The second line contains  space-separated strings, each .
The third line contains  space-separated strings, each .

Constraints

• .
• Each word consists of English alphabetic letters (i.e.,  to  and  to ).

Output Format

Print Yes if he can use the magazine to create an untraceable replica of his ransom note. Otherwise, print No.

Sample Input 0

6 4
give me one grand today night
give one grand today

Sample Output 0

Yes

Sample Input 1

6 5
two times three is not four
two times two is four

Sample Output 1

No

Explanation 1

'two' only occurs once in the magazine.

Sample Input 2

7 4
ive got a lovely bunch of coconuts
ive got some coconuts

Sample Output 2

No

Explanation 2

Harold's magazine is missing the word .

Solution

import java.util.HashMap;
import java.util.HashSet;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

public class Soru04 {
 
 static void checkMagazine(String[] magazine, String[] note) {
  Hashtable<String, Integer> magazineMap = new Hashtable<String, Integer>();
        
        for(String s : magazine){
            if(magazineMap.containsKey(s)){
                magazineMap.put(s, magazineMap.get(s) + 1);
            }else{
                magazineMap.put(s, 1);
            }
        }
        boolean flag = true;         
        for(String s : note){
            if(!magazineMap.containsKey(s)){
               flag=false;
             break;
            }            
            int counter = magazineMap.get(s) - 1;
            
            if(counter == 0){
                magazineMap.remove(s);
            }else{
                magazineMap.put(s, counter);
            }
        }
         
        if(flag==false) {
        System.out.println("No");
        }else {
         System.out.println("Yes");
        }
  
    }
 public static void main(String[] args) {
  // TODO Auto-generated method stub
  String s1[] = new String[] {"two", "times", "three", "is","not", "four"};
  String s2[] = new String[] {"two", "times", "two", "is", "four"};
  checkMagazine(s1, s2);
 }

}