LeetCode/cpp/sum-of-absolute-differences-in-a-sorted-array.cpp

#include <algorithm>
#include <cassert>
#include <numeric>
#include <vector>

class Solution {
  public:
    std::vector<int> getSumAbsoluteDifferences(const std::vector<int> &nums) {
        auto total = std::accumulate(nums.begin(), nums.end(), 0);

        auto left = 0;
        std::vector<int> result;
        for (auto i = 0u; i < nums.size(); ++i) {
            auto left_diff = i * nums[i] - left;

            auto right = total - nums[i] - left;
            auto right_diff = right - (nums.size() - i - 1) * nums[i];

            result.push_back(left_diff + right_diff);

            left += nums[i];
        }

        return result;
    }
};

int main() {
    Solution s;

    assert((s.getSumAbsoluteDifferences(std::vector{2, 3, 5}) ==
            std::vector{4, 3, 5}));
    assert((s.getSumAbsoluteDifferences(std::vector{1, 4, 6, 8, 10}) ==
            std::vector{24, 15, 13, 15, 21}));
    return 0;
}