MinimumElementsToAddToFormAGivenSum.cpp

// Source : https://leetcode.com/problems/minimum-elements-to-add-to-form-a-given-sum/
// Author : Hao Chen
// Date   : 2021-03-07

/***************************************************************************************************** 
 *
 * You are given an integer array nums and two integers limit and goal. The array nums has an 
 * interesting property that abs(nums[i]) <= limit.
 * 
 * Return the minimum number of elements you need to add to make the sum of the array equal to goal. 
 * The array must maintain its property that abs(nums[i]) <= limit.
 * 
 * Note that abs(x) equals x if x >= 0, and -x otherwise.
 * 
 * Example 1:
 * 
 * Input: nums = [1,-1,1], limit = 3, goal = -4
 * Output: 2
 * Explanation: You can add -2 and -3, then the sum of the array will be 1 - 1 + 1 - 2 - 3 = -4.
 * 
 * Example 2:
 * 
 * Input: nums = [1,-10,9,1], limit = 100, goal = 0
 * Output: 1
 * 
 * Constraints:
 * 
 * 	1 <= nums.length <= 105
 * 	1 <= limit <= 106
 * 	-limit <= nums[i] <= limit
 * 	-109 <= goal <= 109
 ******************************************************************************************************/

class Solution {
public:
    long sum(vector<int>& nums) {
        long s = 0;
        for (auto n : nums) {
            s += n;
        }
        return s;
    }
    int minElements(vector<int>& nums, int limit, int goal) {
        long s = sum(nums);
        return (abs(goal - s) + limit -1) / limit;
    }
};