1475. Final Prices With a Special Discount in a Shop

Problem

You are given an integer array prices where prices[i] is the price of the ith item in a shop.

There is a special discount for items in the shop. If you buy the ith item, then you will receive a discount equivalent to prices[j] where j is the minimum index such that j > i and prices[j] <= prices[i]. Otherwise, you will not receive any discount at all.

Return an integer array answer where answer[i] is the final price you will pay for the ith item of the shop, considering the special discount.

  Example 1:

Input: prices = [8,4,6,2,3]
Output: [4,2,4,2,3]
Explanation: 
For item 0 with price[0]=8 you will receive a discount equivalent to prices[1]=4, therefore, the final price you will pay is 8 - 4 = 4.
For item 1 with price[1]=4 you will receive a discount equivalent to prices[3]=2, therefore, the final price you will pay is 4 - 2 = 2.
For item 2 with price[2]=6 you will receive a discount equivalent to prices[3]=2, therefore, the final price you will pay is 6 - 2 = 4.
For items 3 and 4 you will not receive any discount at all.

Example 2:

Input: prices = [1,2,3,4,5]
Output: [1,2,3,4,5]
Explanation: In this case, for all items, you will not receive any discount at all.

Example 3:

Input: prices = [10,1,1,6]
Output: [9,0,1,6]

  Constraints:

• 1 <= prices.length <= 500

• 1 <= prices[i] <= 1000

Solution

/**
 * @param {number[]} prices
 * @return {number[]}
 */
var finalPrices = function(prices) {
    var res = Array.from(prices);
    for (var i = 0; i < prices.length; i++) {
        for (var j = i + 1; j < prices.length; j++) {
            if (prices[j] <= prices[i]) {
                res[i] = prices[i] - prices[j];
                break;
            }
        }
    }
    return res;
};

Explain:

nope.

Complexity:

• Time complexity : O(n ^ 2).
• Space complexity : O(n).