Given an array of non-negative integers, you are initially positioned at the first index of the array.


Each element in the array represents your maximum jump length at that position. 


Determine if you are able to reach the last index.

For example:
A = [2,3,1,1,4], return true.


A = [3,2,1,0,4], return false.
 

class Solution(object):
    def canJump(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        pos = 0
        bound = len(nums)
        while pos < len(nums) - 1:
            dis = nums[pos]
            if dis == 0:
                return False
            farthest = posToFarthest = 0
            for i in xrange(pos + 1, min(pos + dis + 1, bound)):
                canReach = i + nums[i]
                if i == len(nums) - 1:
                    return True
                if canReach > farthest:
                    farthest = canReach
                    posToFarthest = i
            pos = posToFarthest
        return True if pos >= len(nums) - 1 else False