Fixed Point in Python

Suppose we have an array A of unique integers sorted in ascending order, we have to return the smallest index i that satisfies A[i] == i. Return -1 if no such i exists. So if the array is like [-10,-5,0,3,7], then the output will be 3, as A[3] = 3 the output will be 3.

To solve this, we will follow these steps −

• For i in range 0 to length of A
  • if i = A[i], then return i
• return -1

Example(Python)

Let us see the following implementation to get a better understanding −

 Live Demo

class Solution(object):
   def fixedPoint(self, A):
      for i in range(len(A)):
         if i == A[i]:
            return i
      return -1
ob1 = Solution()
print(ob1.fixedPoint([-10,-5,0,3,7]))

Input

[-10,-5,0,3,7]

Output

3

Arnab Chakraborty

Updated on: 28-Apr-2020

1K+ Views

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