jump-game.py

# Time:  O(n)
# Space: O(1)
#
# 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:
    # @param A, a list of integers
    # @return a boolean
    def canJump(self, A):
        reachable = 0
        for i, length in enumerate(A):
            if i > reachable:
                break
            reachable = max(reachable, i + length)
        return reachable >= len(A) - 1
    
if __name__ == "__main__":
    print Solution().canJump([2,3,1,1,4])
    print Solution().canJump([3,2,1,0,4])