Add greedy solution for Jump Game.

Author: trekhleb

src/algorithms/uncategorized/jump-game/grdJumpGame.js

@@ -0,0 +1,26 @@
+/**
+ * GREEDY approach of solving Jump Game.
+ *
+ * @param {number[]} numbers - array of possible jump length.
+ */
+export default function grdJumpGame(numbers) {
+ // The "good" cell is a cell from which we may jump to the last cell of the numbers array.
+
+ // The last cell in numbers array is for sure the "good" one since it is our goal to reach.
+ let leftGoodPosition = numbers.length - 1;
+
+ // Go through all numbers from right to left.
+ for (let numberIndex = numbers.length - 2; numberIndex >= 0; numberIndex -= 1) {
+ // If we can reach the "good" cell from the current one then for sure the current
+ // one is also "good". Since after all we'll be able to reach the end of the array
+ // from it.
+ const maxCurrentJumpLength = numberIndex + numbers[numberIndex];
+ if (maxCurrentJumpLength >= leftGoodPosition) {
+ leftGoodPosition = numberIndex;
+ }
+ }
+
+ // If the most left "good" position is the zero's one then we may say that it IS
+ // possible jump to the end of the array from the first cell;
+ return leftGoodPosition === 0;
+}