Are Similar?

Two arrays are called similar if one can be obtained from another by swapping at most one pair of elements in one of the arrays.

Given two arrays a and b, check whether they are similar.

Example

• For a = [1, 2, 3] and b = [1, 2, 3], the output should be

  are_similar(a, b) = true

  The arrays are equal, no need to swap any elements.

• For a = [1, 2, 3] and b = [2, 1, 3], the output should be

  are_similar(a, b) = true

  We can obtain b from a by swapping 2 and 1 in b.

• For a = [1, 2, 2] and b = [2, 1, 1], the output should be

  are_similar(a, b) = false

  Any swap of any two elements either in a or in b won't make a and b equal.

Solution

PYTHON

def are_similar(a, b):
    return sorted(a) == sorted(b) and sum([i != j for i, j in zip(a, b)]) <= 2


print(are_similar([1, 2, 3, 4], [1, 3, 2, 4]))

JAVASCRIPT

// Input:
// a: [1, 2, 3]
// b: [2, 1, 3]

// Expected Output:
// true

function areSimilar(a, b) {
  if (a.length !== b.length) {
    return false;
  }
  let diff = 0;
  for (let i = 0; i < a.length; i++) {
    if (a[i] !== b[i]) {
      diff++;
    }
  }
  if (diff > 2) {
    return false;
  }
  a.sort();
  b.sort();
  for (let i = 0; i < a.length; i++) {
    if (a[i] !== b[i]) {
      return false;
    }
  }
  return true;
}

print(areSimilar([1, 2, 3, 4], [1, 3, 2, 4]));