55. Jump Game

dynamic programming

class Solution(object):
    def canJump(self, nums):
        """
        :type nums: List[int]
        :rtype: bool
        """
        l=len(nums)
        if l==1 :return True 
        d=[0 for i in xrange(l)]
        d[0]=nums[0]
        if d[0]==0: return False
        for i in xrange(1,l):
            if nums[i]==0 and d[i-1]<=i:return False
            d[i]=max(d[i-1],i+nums[i])
            if d[i]>=l-1: return True
        return False

class Solution(object):
    def canJump(self, nums):
        """
        :type nums: List[int]
        :rtype: bool
        """
        reachable=0
        for i, length in enumerate(nums):
            if i>reachable:
                break
            reachable=max(reachable,i+length)
        return reachable>=len(nums)-1