1014. Best Sightseeing Pair

Description

You are given an integer array values where values[i] represents the value of the ith sightseeing spot. Two sightseeing spots i and j have a distance j - i between them.

The score of a pair (i < j) of sightseeing spots is values[i] + values[j] + i - j: the sum of the values of the sightseeing spots, minus the distance between them.

Return the maximum score of a pair of sightseeing spots.

 

Example 1:

Input: values = [8,1,5,2,6]
Output: 11
Explanation: i = 0, j = 2, values[i] + values[j] + i - j = 8 + 5 + 0 - 2 = 11

Example 2:

Input: values = [1,2]
Output: 2

 

Constraints:

• 2 <= values.length <= 5 * 104
• 1 <= values[i] <= 1000

 

Solutions

Solution: Dynamic Programming

• Time complexity: O(n)
• Space complexity: O(1)

 

JavaScript

/**
 * @param {number[]} values
 * @return {number}
 */
const maxScoreSightseeingPair = function (values) {
  const n = values.length;
  let preMaxScore = values[0];
  let result = 0;

  for (let index = 1; index < n; index++) {
    const score = values[index];

    result = Math.max(preMaxScore + score - index, result);
    preMaxScore = Math.max(score + index, preMaxScore);
  }
  return result;
};