Program to find largest distance pair from two list of numbers in Python

PythonServer Side ProgrammingProgramming

Suppose we have two list of numbers called A and B, and their lengths are same. We have to find the maximum value for all 0 ≤ i < j < n: |a[i] - a[j]| + |b[i] - b[j]| + |i - j|

So, if the input is like A = [2, 4, 10, 6] B = [3, 4, 7, 5], then the output will be 14, as when i = 0 and j = 2 and we get |2 - 10| + |3 - 7| + |1 - 3|.

To solve this, we will follow these steps −

  • ans := 0
  • n := size of a
  • for each pair (s, t) in [(-1, -1) ,(-1, 1) ,(1, -1) ,(1, 1) ], do
    • cur_min := infinity
    • cur_max := -infinity
    • for i in range 0 to n, do
      • tmp := s * a[i] + t * b[i] + i
      • cur_min := minimum of cur_min, tmp
      • cur_max := maximum of cur_max, tmp
    • ans := maximum of ans, (cur_max - cur_min)
  • return ans

Let us see the following implementation to get better understanding −

Example

 Live Demo

class Solution:
   def solve(self, a, b):
      ans = 0
      n = len(a)
      for s, t in [(-1, -1), (-1, 1), (1, -1), (1, 1)]:
         cur_min = float("inf")
         cur_max = float("-inf")
         for i in range(n):
            tmp = s * a[i] + t * b[i] + i
            cur_min = min(cur_min, tmp)
            cur_max = max(cur_max, tmp)
            ans = max(ans, cur_max - cur_min)
      return ans
ob = Solution()
A = [2, 4, 10, 6]
B = [3, 4, 7, 5]
print(ob.solve(A, B))

Input

[2, 4, 10, 6],[3, 4, 7, 5]

Output

14
raja
Published on 19-Nov-2020 06:42:43
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