Codility301-Time Complexity-FrogJmp.js

//https://app.codility.com/demo/results/training6WVD28-Z3Y/
// Task description
// A small frog wants to get to the other side of the road. The frog is currently located at position X and wants to get to a position greater than or equal to Y. The small frog always jumps a fixed distance, D.

// Count the minimal number of jumps that the small frog must perform to reach its target.

// Write a function:

// function solution(X, Y, D);

// that, given three integers X, Y and D, returns the minimal number of jumps from position X to a position equal to or greater than Y.

// For example, given:

//   X = 10
//   Y = 85
//   D = 30
// the function should return 3, because the frog will be positioned as follows:

// after the first jump, at position 10 + 30 = 40
// after the second jump, at position 10 + 30 + 30 = 70
// after the third jump, at position 10 + 30 + 30 + 30 = 100
// Write an efficient algorithm for the following assumptions:

// X, Y and D are integers within the range [1..1,000,000,000];
// X ≤ Y.

function solution(X, Y, D) {
  // write your code in JavaScript (Node.js 8.9.4)
  if (X == Y) {return 0}
  else if (D > (Y-X)) { return 1}
  else { 
    return Math.ceil((Y-X)/D)
  }
    
}