Leetcode 3601. Find Drivers with Improved Fuel Efficiency

Compute each driver's average fuel efficiency (distance_km / fuel_consumed) separately for the first half (Jan–Jun) and second half (Jul–Dec) of the year, include only drivers who have trips in both halves, and calculate the improvement as (second_half_avg − first_half_avg) rounded to two decimals. Return driver names with their first_half, second_half, and improvement values ordered by improvement descending then driver name ascending.