You’ve been provided with the nums integer array, representing the series of squares. The player starts at the first index and, following the rules of the game, tries to reach the last index. If the player can reach the last index, your function returns TRUE; otherwise, it returns FALSE.

1-jump-game.js

export function jumpGame(nums) {
  // take last element as our target
  let target = nums.length - 1;
  // start iterating from the element preceding the last, backwards
  for (let i = nums.length - 2; i >= 0; --i) {
    const preceding = i;
    const diff = target - preceding;
    // the target element is reachable from the preceding element,
    // if preceding element value is greater or equal to the difference between target and preceding index
    // for example, element at index 5 is reachable from element at index 4 if value at index 4 is 1 or more
    // element at index 4 is reachable from element at index 1 if value at index 1 is 3 or more
    if (nums[preceding] >= diff) {
      // if target is reachable, make preceding element our new target
      target = preceding;
    }
  }
  // if we reached element at index 0, it means we have a path, otherwise we don't have a path
  return target === 0;
}

2-README.md