javascript - Are they the "same"? CodeWars - Stack Overflow

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HERE IS THE FULL QUESTION DESCRIPTION

Given two arrays a and b write a function p(a, b) (pSame(a, b) in Clojure) that checks whether the two arrays have the "same" elements, with the same multiplicities. "Same" means, here, that the elements in b are the elements in a squared, regardless of the order.

Examples

Valid arrays

a = [121, 144, 19, 161, 19, 144, 19, 11]  
b = [121, 14641, 20736, 361, 25921, 361, 20736, 361]

p(a, b) returns true because in b:

1. 121 is the square of 11,
2. 14641 is the square of 121,
3. 20736 the square of 144,
4. 361 the square of 19,
5. 25921 the square of 161, and so on.

It gets obvious if we write b's elements in terms of squares:

Invalid arrays

a = [121, 144, 19, 161, 19, 144, 19, 11] 
b = [11*11, 121*121, 144*144, 19*19, 161*161, 19*19, 144*144, 19*19]

If we change the first number to something else, p may not return true anymore:

a = [121, 144, 19, 161, 19, 144, 19, 11]  
b = [132, 14641, 20736, 361, 25921, 361, 20736, 361]

p(a,b) returns false because in b, 132 is not the square of any number of a.

a = [121, 144, 19, 161, 19, 144, 19, 11]  
b = [121, 14641, 20736, 36100, 25921, 361, 20736, 361]

p(a,b) returns false because in b, 36100 is not the square of any number of a.

Remarks

1. a or b might be [] (all languages).
2. a or b might be nil or null or None (except in Haskell, Elixir, C++, Rust).
3. If a or b are nil (or null or None), the problem doesn't make sense so return false.
4. If a or b are empty the result is evident by itself.

Note for C

1. The two arrays have the same size (> 0) given as parameter in function p.

MY QUESTION:

Can you e up with a test case where I do not meet the desired specefications??

I am stuck on 1 basic test not being passed (expected result: true but my code returns false)

MY CODE ATTEMPT

function isTrue(el){
  return el === true;
}

function p(array1, array2){
  if(array1.length === 0 || array2.length === 0){
    return false;
  }
  var arr = array1.map(function(num){return num*num});
  var arr2 = [];
  for(var i = 0; i < arr.length; i++){
    if(array2.includes(arr[i])){
      arr2.push(true);
      var a = array2.indexOf(arr[i]);
     array2.splice(a,1);
    } else{
      arr2.push(false);
    }
  }
  return arr2.includes(false) ? false : true;
}

HERE IS THE FULL QUESTION DESCRIPTION

Given two arrays a and b write a function p(a, b) (pSame(a, b) in Clojure) that checks whether the two arrays have the "same" elements, with the same multiplicities. "Same" means, here, that the elements in b are the elements in a squared, regardless of the order.

Examples

Valid arrays

a = [121, 144, 19, 161, 19, 144, 19, 11]  
b = [121, 14641, 20736, 361, 25921, 361, 20736, 361]

p(a, b) returns true because in b:

1. 121 is the square of 11,
2. 14641 is the square of 121,
3. 20736 the square of 144,
4. 361 the square of 19,
5. 25921 the square of 161, and so on.

It gets obvious if we write b's elements in terms of squares:

Invalid arrays

a = [121, 144, 19, 161, 19, 144, 19, 11] 
b = [11*11, 121*121, 144*144, 19*19, 161*161, 19*19, 144*144, 19*19]

If we change the first number to something else, p may not return true anymore:

a = [121, 144, 19, 161, 19, 144, 19, 11]  
b = [132, 14641, 20736, 361, 25921, 361, 20736, 361]

p(a,b) returns false because in b, 132 is not the square of any number of a.

a = [121, 144, 19, 161, 19, 144, 19, 11]  
b = [121, 14641, 20736, 36100, 25921, 361, 20736, 361]

p(a,b) returns false because in b, 36100 is not the square of any number of a.

Remarks

1. a or b might be [] (all languages).
2. a or b might be nil or null or None (except in Haskell, Elixir, C++, Rust).
3. If a or b are nil (or null or None), the problem doesn't make sense so return false.
4. If a or b are empty the result is evident by itself.

Note for C

1. The two arrays have the same size (> 0) given as parameter in function p.

MY QUESTION:

Can you e up with a test case where I do not meet the desired specefications??

I am stuck on 1 basic test not being passed (expected result: true but my code returns false)

MY CODE ATTEMPT

function isTrue(el){
  return el === true;
}

function p(array1, array2){
  if(array1.length === 0 || array2.length === 0){
    return false;
  }
  var arr = array1.map(function(num){return num*num});
  var arr2 = [];
  for(var i = 0; i < arr.length; i++){
    if(array2.includes(arr[i])){
      arr2.push(true);
      var a = array2.indexOf(arr[i]);
     array2.splice(a,1);
    } else{
      arr2.push(false);
    }
  }
  return arr2.includes(false) ? false : true;
}

• javascript
• arrays
• debugging
• pare

Share Improve this question Follow edited Jul 12, 2017 at 12:35 Ethan 44633 silver badges1313 bronze badges asked Jul 12, 2017 at 4:24 George YammineGeorge Yammine 2311 silver badge55 bronze badges 2

• What is the range of the input? I guess you get wired behavior if the input numbers are too large. Consider taking the root of elements in array2 instead of squaring elements in array1. developer.mozilla/en/docs/Web/JavaScript/Reference/… – LudvigH Commented Jul 12, 2017 at 5:32
• I found the solution, apparently if the two arrays were empty I should have returned true. – George Yammine Commented Jul 12, 2017 at 8:31

Add a ment  | 

1 Answer 1

Sorted by: Reset to default 7

The easiest possible way:

const p = (a1, a2) => {
  if (!a1 || !a2 || a1.length !== a2.length) return false;
  return a1.map(x => x * x).sort().toString() === a2.sort().toString();
}

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