jump_game_ii.dart

/*


-* 45. Jump Game II *-

You are given a 0-indexed array of integers nums of length n. You are initially positioned at nums[0].

Each element nums[i] represents the maximum length of a forward jump from index i. In other words, if you are at nums[i], you can jump to any nums[i + j] where:

0 <= j <= nums[i] and
i + j < n
Return the minimum number of jumps to reach nums[n - 1]. The test cases are generated such that you can reach nums[n - 1].

 

Example 1:

Input: nums = [2,3,1,1,4]
Output: 2
Explanation: The minimum number of jumps to reach the last index is 2. Jump 1 step from index 0 to 1, then 3 steps to the last index.
Example 2:

Input: nums = [2,3,0,1,4]
Output: 2
 

Constraints:

1 <= nums.length <= 104
0 <= nums[i] <= 1000


*/

import 'dart:math';

class A {
  int jump(List<int> nums) {
    int ans = 0;
    int size = nums.length;
    int currentEnd = 0;
    int currentFarthest = 0;

    for (int i = 0; i < size - 1; i++) {
      currentFarthest = max(currentFarthest, i + nums[i]);
      if (i == currentEnd) {
        ans++;
        currentEnd = currentFarthest;
      }
    }
    return ans;
  }
}