FrogJmp.js

// 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
// Assume that:

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

// expected worst-case time complexity is O(1);
// expected worst-case space complexity is O(1).
// Copyright 2009–2018 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.

// 33% //
// function solution(X, Y, D) {
//   var newPos = X;
//   var jumps = 0;
//   do {
//     jumps += 1;
//     newPos +=  D;  
//   } while (newPos < Y);
//   return jumps;
// }

// 44% //
function solution(X, Y, D) {
  var newPos = X;
  var jumps = 0;
  while (newPos < Y) {
    jumps += 1;
    newPos +=  D;  
  };
  return jumps;
}

// 44% //


// function solution(X, Y, D) {
//   if (X < Y) {
//     jumps += 1;
//     X +=  D; 
//     solution(X,Y,D)
//   }

//   return jumps;
// }
// var jumps = 0;

console.log(solution(3,999111321,7));