shad-go/hotelbusiness/hotels.go

//go:build !solution

package hotelbusiness

import "math"

type Guest struct {
	CheckInDate  int
	CheckOutDate int
}

type Load struct {
	StartDate  int
	GuestCount int
}

func ComputeLoad(guests []Guest) []Load {
	if len(guests) == 0 {
		return []Load{}
	}
	minDate, maxDate := math.MaxInt, math.MinInt
	loadsNoEmptyDays := make(map[int]int)
	for _, guest := range guests {
		if guest.CheckInDate < minDate {
			minDate = guest.CheckInDate
		}
		if guest.CheckOutDate > maxDate {
			maxDate = guest.CheckOutDate
		}
		for i := guest.CheckInDate; i < guest.CheckOutDate; i++ {
			loadsNoEmptyDays[i]++
		}
	}
	loads, prevGuestCount := make([]Load, 0), 0
	for i := minDate; i <= maxDate; i++ {
		guestCount := loadsNoEmptyDays[i]
		if prevGuestCount == guestCount {
			continue
		}
		loads = append(loads, Load{i, guestCount})
		prevGuestCount = guestCount
	}
	return loads
}