SeaCode

Appearance

Maximum Absolute Difference ​

Problem Description ​

You are given an array of N integers, A1, A2 ,..., AN.

Return maximum value of f(i, j) for all 1 ≤ i, j ≤ N.

f(i, j) is defined as |A[i] - A[j]| + |i - j|, where |x| denotes absolute value of x.

Problem Constraints

1 <= |A| <= 10^5
-10^9 <= Ai <= 10^9

Input Format

The first argument is an integer array A.

Output Format

Return an integer equal to the maximum value of f(i, j)

Example Input

A = [1, 3, -1]

Example Output

5

Example Explanation

Given A = [1, 3, -1], 
f(1, 1) = f(2, 2) = f(3, 3) = 0
f(1, 2) = f(2, 1) = |1 - 3| + |1 - 2| = 3
f(1, 3) = f(3, 1) = |1 - (-1)| + |1 - 3| = 4
f(2, 3) = f(3, 2) = |3 - (-1)| + |2 - 3| = 5
The maximum value is 5, which is of f(2, 3)

Solution ​

swift
import Foundation

class Solution {
	func maxArr(_ A: inout [Int]) -> Int {
        let len = A.count
        var result = 0
        
        var min1 = Int.max
        var max1 = Int.min
        
        var min2 = Int.max
        var max2 = Int.min
        
        for i in 0..<len {
            var v = A[i] + i
            if v < min1 {
                min1 = v
            }
            if v > max1 {
                max1 = v
            }
            
            v = A[i] - i
            if v < min2 {
                min2 = v
            }
            if v > max2 {
                max2 = v
            }
        }
        if (max1 - min1 ) > result {
            result = max1 - min1
        }
        
        if (max2 - min2 ) > result {
            result = max2 - min2
        }
        
        
        
        
        // for i in 0..<len {
        //     for j in (i+1)..<len {
        //         let v = abs(A[i] - A[j]) + j - i
        //         if v > result {
        //             result = v
        //         }
        //     }
        // }
        return result
	}
}

References ​