Dimensi TutupBotol: Java Challenge

Showing posts with label Java Challenge. Show all posts

Wednesday, June 15, 2016

splitOdd10 - Recursive - Java & C#

Given an array of ints, is it possible to divide the ints into two groups, so that the sum of one group is a multiple of 10, and the sum of the other group is odd. Every int must be in one group or the other. Write a recursive helper method that takes whatever arguments you like, and make the initial call to your recursive helper from splitOdd10(). (No loops needed.)

splitOdd10([5, 5, 5]) → true
splitOdd10([5, 5, 6]) → false
splitOdd10([5, 5, 6, 1]) → true

Java :

public boolean splitOdd10(int[] nums) {
   return helper(0, nums, 0);
}

public boolean helper(int index, int[] nums, int result)
  { 
    if(index >= nums.length)
      {
        if ((result % 10) % 2 == 1) return true;
        else return false;
      }

    return helper(index + 1, nums, result + nums[index]);
  }

Test Result:

C#:

public static Boolean splitOdd10(int[] nums)
        {
            return helper(0, nums, 0);
        }

public static Boolean helper(int index, int[] nums, int result)
        { 
            if(index >= nums.Length)
            {
                if ((result % 10) % 2 == 1) return true;
                else return false;
            }

            return helper(index + 1, nums, result + nums[index]);
        }

Test :

stringClean - Recursive - Java & C#

Given a string, return recursively a "cleaned" string where adjacent chars that are the same have been reduced to a single char. So "yyzzza" yields "yza".

stringClean("yyzzza") → "yza"
stringClean("abbbcdd") → "abcd"
stringClean("Hello") → "Helo"

Java :

public String stringClean(String str) {
  //Stop Condition
  if(str.length()<2) return str;
  
  //Main recursive process
  int index = 0;
  for(index=0; index+1<str.length(); index++)
  {
    if(str.charAt(index) != str.charAt(index+1)) break;
  }
  return str.charAt(index)+stringClean(str.substring(index+1));
}

Test Result:

C#:

 public static string stringClean(string str)
        { 
            //kondisi setop
            if (str.Length < 2) return str;

            //main rekursif
            int index = 0;
            for (index=0; index+1 < str.Length; index++)
            {
                if (str[index] != str[index + 1]) break;
            }

            return str[index] + stringClean(str.Substring(index+1));

        }

Test Result :

allStar - Recursive - Java & C#

Given a string, compute recursively a new string where all the adjacent chars are now separated by a "*".

allStar("hello") → "h*e*l*l*o"
allStar("abc") → "a*b*c"
allStar("ab") → "a*b"
Java :

public static String allStar(String str)
 {
  //Stop Condition
  if(str.length()<1) return "";
  if(str.length() == 1) return str+"*";
  
  
  //Main recursive process
  return str.charAt(0)+"*"+allStar(str.substring(1));
 }

Hasil :

C# :

   public static string allStar(String str)
        { 
            //Kondisi stop
            if (str.Length < 1) return "";
            if (str.Length == 1) return str;


            //Proses rekursif
            return str[0] + "*" + allStar(str.Substring(1));
        }

Hasil :

array11 - Recursive - Java & C#

Given an array of ints, compute recursively the number of times that the value 11 appears in the array. We'll use the convention of considering only the part of the array that begins at the given index. In this way, a recursive call can pass index+1 to move down the array. The initial call will pass in index as 0.

array11([1, 2, 11], 0) → 1
array11([11, 11], 0) → 2
array11([1, 2, 3, 4], 0) → 0

Java :

public static int array11(int[] nums, int index)
 {
  //Stop Condition
  if(nums.length == 0 ) return 0;
  if(nums.length == 1)
  {
   if(nums[0] == 11) return 1;
   else return 0;
  }
  
  //Main recursive process
  int[] temp = Arrays.copyOfRange(nums, index+1, nums.length);
  if(nums[index] == 11) return 1+array11(temp,index);
  else return array11(temp,index);
 }

Test Result :

C# :

 public static int array11(int[] nums, int index)
        { 
            //Kondisi stop
            if (nums.Length == 0) return 0;
            if (nums.Length == 1)
            {
                if (nums[0] == 11) return 1;
                else return 0;
            }

            //Proses rekursif
            int[] temp = new int[nums.Length - index - 1];
            System.Array.Copy(nums, index+1, temp, 0, temp.Length);
            if (nums[index] == 11) return 1 + array11(temp, index);
            else return array11(temp, index);
        }

Test Result:

array6 - Recursive - Java & C#

Given an array of ints, compute recursively if the array contains a 6. We'll use the convention of considering only the part of the array that begins at the given index. In this way, a recursive call can pass index+1 to move down the array. The initial call will pass in index as 0.

array6([1, 6, 4], 0) → true
array6([1, 4], 0) → false
array6([6], 0) → true
Java :

public static boolean array6(int[] nums, int index)
 {
  //Stop condition
  if(nums.length == 0) return false;
  if(nums.length == 1)
  {
   if(nums[0]== 6) return true;
   else return false;
  }
  
  //Main process
  if(nums[index] == 6) return true;
  int[] temp = Arrays.copyOfRange(nums, index+1, nums.length);
        
  return array6(temp,index);
 }

Test Result:

C# :

public static Boolean array6(int[] nums, int index)
        { 
            //stop condition
            if (nums.Length == 0) return false;
            if (nums.Length == 1)
            {
                if (nums[0] == 6) return true;
                else return false;
            }
            if(nums[index] == 6) return true;

            //Main recursive process
            int[] temp = new int[nums.Length-index-1];
            System.Array.Copy(nums,index+1,temp,0,temp.Length);
            return array6(temp, index);
        }

Test Result:

Tuesday, June 14, 2016

changePi - Recursive - Java & C#

Given a string, compute recursively (no loops) a new string where all appearances of "pi" have been replaced by "3.14".

changePi("xpix") → "x3.14x"
changePi("pipi") → "3.143.14"
changePi("pip") → "3.14p"

Java :

public String changePi(String str) {
  if (str.length() < 1) return "";
 int index = str.indexOf("pi");
 if (index < 0) return str;
 String temp = str.substring(0, index);
 return temp+"3.14"+changePi(str.substring(index+2, str.length()));
}

Test result:

C# :

public static String changePi(String str)
 {
            if (str.Length < 1) return "";
            int index = str.IndexOf("pi");
            if (index < 0 ) return str;
            String temp0 = str.Substring(0, index);
            String temp = str.Substring(index+2, str.Length-(2+index));
            return temp0+"3.14" + changePi(temp);
 }

Test Result :

changeXY - Recursive - Java & C#

Given a string, compute recursively (no loops) a new string where all the lowercase 'x' chars have been changed to 'y' chars.

changeXY("codex") → "codey"
changeXY("xxhixx") → "yyhiyy"
changeXY("xhixhix") → "yhiyhiy"
Java :

public String changeXY(String str) {
  if(str.length() < 1) return "";
  char temp = str.charAt(str.length()-1);
  if(temp == 'x') temp = 'y';
  return changeXY(str.substring(0,str.length()-1))+temp;
}

Test Result:

C#:

public static String changeXY(String str)
        {
            if (str.Length < 1) return "";
            Char temp = str[str.Length - 1];
            if (temp == 'x') temp = 'y';
            return changeXY(str.Substring(0, str.Length - 1)) + temp;
        }

Test Result :

countHi - Recursive

Given a string, compute recursively (no loops) the number of times lowercase "hi" appears in the string.

countHi("xxhixx") → 1
countHi("xhixhix") → 2
countHi("hi") → 1

C# :

  public static int countHi(String str)
        { 
            //stop condition
            if (str.Length < 2) return 0;

            //Process
            int index = str.IndexOf("hi");
            if (index < 0) return 0;
            return 1 + countHi(str.Substring(index + 1, str.Length - (1 + index)));
           
        }

Result :

CountX - Recursive

Given a string, compute recursively (no loops) the number of lowercase 'x' chars in the string.

countX("xxhixx") → 4
countX("xhixhix") → 3
countX("hi") → 0

Hisoka's Jutsu :

public int countX(String str) {
  if (str.length() == 0) return 0;
 if(str.charAt(str.length()-1) == 'x') return 1+countX(str.substring(0, str.length()-1));
 return countX(str.substring(0, str.length()-1));
}

Output :

Ooowh... btw... if we want to write countX in C#, it will gonna be like this :

  public static int countX(String str)
        {
            //stop condition
            if (str.Length == 0) return 0;

            if (str[(str.Length - 1)] == 'x') return 1 + countX(str.Substring(0, str.Length - 1));
            return countX(str.Substring(0, str.Length - 1));
        }

The output is same, you can check it here

PowerN - Recursion

Given base and n that are both 1 or more, compute recursively (no loops) the value of base to the n power, so powerN(3, 2) is 9 (3 squared).

powerN(3, 1) → 3
powerN(3, 2) → 9
powerN(3, 3) → 27

Java :

public int powerN(int base, int n) {
  if(n == 0 ) return 1;
  if(n == 1) return base;
  return base*powerN(base,n-1);
}

Output :

Oooowh...btw... We can use DinamycProgramming style here.... It will gonna look like this :

public int powerN(int base, int n) {
 int[] hasil = new int[n];
 hasil[0] = base;
 for(int i=1; i<n; i++)
 {
   hasil[i] = base*hasil[i-1];
 }
 return hasil[n-1];
}

The output will be same, but DinamycProgramming style is faster than recursive at a big n... :D

Monday, June 13, 2016

Check Single Swap Array in Java

Here is the code :

 public static boolean CheckSingleSwap(int[] A)
 {
  int count = 0;
  int[]B = Arrays.copyOf(A, A.length); 
  Arrays.sort(B);  
  for(int i=0; i<A.length; i++)
  {
   if(A[i] != B[i]) count++;
  }
  
  if(count > 2) return false;
  return true;
 }

Test case :

System.out.println("Test Single Swap for Array...");
 int[]A = {1,2};
     int[]B = {1,3,6,3,5,5,3,7,7};
     int[]C = {1, 4, 5, 6, 7, 2}; 
     int[]D = {1,2,3,4,5,6,7,8,9,10,11,2,45,56,67,78,89,90,123,124,1245566778};
     int[]D1 = {1,2,3,4,5,6,7,8,9,10,11,2,45,56,67,78,89,90,2,123,124,1245566778};
     int[]E = {1, 5, 3, 3, 7} ;
     int[]F= {1, 3, 5};
     int[]G = {1,5,3};
     int[]H = {1, 2, 6, 3, 4, 5};

     System.out.println("A : "+CheckSingleSwap(A));
     System.out.println("B : "+CheckSingleSwap(B));
     System.out.println("C : "+CheckSingleSwap(C));
     System.out.println("D : "+CheckSingleSwap(D));
     System.out.println("D1 : "+CheckSingleSwap(D1));
     System.out.println("E : "+CheckSingleSwap(E));
     System.out.println("F : "+CheckSingleSwap(F));
     System.out.println("H : "+CheckSingleSwap(H));

Output :

A : true
B : true
C : false
D : false
D1 : false
E : true
F : true
H : false

Thursday, June 9, 2016

ArrayInversionCount Codility - Road to 100% - Java

Task Link : https://codility.com/programmers/task/array_inversion_count/

First solution (72%):

class Solution {
    public int solution(int[] A) {
        // write your code in Java SE 8
        int count = 0;
  for(int p=0; p<A.length; p++)
  {
   for(int q=p+1; q<A.length; q++)
   {
    if(A[p]>A[q]) count++;
   }
  }
  if(count > 1000000000) return -1;
  return count;
    }
}

Result : https://codility.com/demo/results/trainingXBUESU-MQG/

Second Solution (100%) :

// you can also use imports, for example:
 import java.util.*;

// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");

class Solution {
    public int solution(int[] arr) {
        // write your code in Java SE 8
        if (arr.length < 2)
         return 0;

     int m = (arr.length + 1) / 2;
     int left[] = Arrays.copyOfRange(arr, 0, m);
     int right[] = Arrays.copyOfRange(arr, m, arr.length);

        int result = solution(left) + solution(right) + merge(arr, left, right);
        if(result > 1000000000) return -1;
     return result;
    }
    
    
    
    int merge(int[] arr, int[] left, int[] right) {
     int i = 0, j = 0, count = 0;
     while (i < left.length || j < right.length) {
         if (i == left.length) {
             arr[i+j] = right[j];
             j++;
         } else if (j == right.length) {
             arr[i+j] = left[i];
             i++;
         } else if (left[i] <= right[j]) {
             arr[i+j] = left[i];
             i++;                
         } else {
             arr[i+j] = right[j];
             count += left.length-i;
             j++;
         }
     }
     return count;
 }
}

Result : https://codility.com/demo/results/training57Y8R2-QK9/