Program to check whether we can reach last position from index 0 in Python

PythonServer Side ProgrammingProgramming

Suppose we have a list of numbers called nums where each number shows the maximum number of jumps we can make; we have to check whether we can reach to the last index starting at index 0 or not.

So, if the input is like nums = [2,5,0,2,0], then the output will be True, as we can jump from index 0 to 1, then jump from index 1 to end.

To solve this, we will follow these steps−

  • n := size of nums

  • arr := an array of size n and fill with false

  • arr[n - 1] := True

  • for i in range n - 2 to 0, decrease by 1, do

    • arr[i] := true if any one of arr[from index i + 1 to i + nums[i]] is true

  • return arr[0]

Let us see the following implementation to get better understanding −

Example

 Live Demo

class Solution:
   def solve(self, nums):
      n = len(nums)
      arr = [False] * n
      arr[n - 1] = True
      for i in range(n - 2, -1, -1):
         arr[i] = any(arr[i + 1 : i + nums[i] + 1])
      return arr[0]
ob = Solution()
nums = [2,5,0,2,0]
print(ob.solve(nums))

Input

[2,5,0,2,0]

Output

True
raja
Published on 09-Oct-2020 17:07:59
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