Thinking process - dp

O(n^2)

dp[i] = the minimum number of jumps needed to reach position i

Thinking process - bfs

O(n)

add reachable elements to a queue

Mistakes

1. don't use queue, otherwise it's O(n^2) as well
2. currIndex is changing, so currMax should be equal to maxIndex

public class Solution {
    public int jump(int[] nums) {
        if (nums.length <= 1) return 0;

        int result = 0;
        int currIndex = 0;
        int maxIndex = 0;
        int currMax = 0;

        while (currIndex < nums.length) {
            result++;
            for (; currIndex <= currMax; ++currIndex) {
                maxIndex = Math.max(maxIndex, currIndex + nums[currIndex]);
                if (maxIndex >= nums.length - 1) {
                    return result;
                }
            }
            currMax = maxIndex;
        }

        return 0;
    }
}