2448.cpp

class Solution {
  public:
    long long minCost(const vector<int> &nums, const vector<int> &cost) {
        const auto calc = [&const](int target) {
            long long res = 0;
            for (int i = 0; i < nums.size(); i++)
                res += (long long)abs(nums[i] - target) * cost[i];
            return res;
        };

        long left = 1L, right = 1000000L;
        for (long num : nums) {
            left = min(left, num);
            right = max(right, num);
        }

        long ans = calc(1);
        while (left < right) {
            long mid = (left + right) / 2;
            long y1 = calc(mid), y2 = calc(mid + 1);
            ans = min(y1, y2);
            if (y1 < y2)
                right = mid;
            else
                left = mid + 1;
        }
        return ans;
    }
};