Go / Golang Sort the slice of pointers to a struct

Question

How do I sort slice of pointer to a struct. I am trying to sort the slice based on the start time.

/**
 * Definition for an Interval.
 * type Interval struct {
 *     Start int
 *     End   int
 * }
 */

func employeeFreeTime(schedule [][]*Interval) []*Interval {
    
    fmt.Println("Schedule initial #", schedule)
    sort.Slice(schedule, func(i,j int) bool{
        return schedule[i].Start < schedule[j].Start
    })
    
    fmt.Println(schedule)
    return nil
    
}

Answer 1

Send in a slice, instead of a slice of slices and you can sort just fine:

/**
* Definition for an Interval.
*/
 type Interval struct {
     Start int
     End   int
 }


func employeeFreeTime(schedule []*Interval) []*Interval {

    fmt.Println("Schedule initial #", schedule)
    sort.Slice(schedule, func(i,j int) bool{
        return schedule[i].Start < schedule[j].Start
    })

    fmt.Println(schedule)
    return nil

}

func main() {
    intervals :=  []*Interval {
        {
            Start: 10,
            End:   100,
        },
        {
            Start: 5,
            End:   100,
        },
    }
    employeeFreeTime(intervals)
}

Answer 2

In case you want to sort all the Interval s among the slice of slice.

func employeeFreeTime(schedule [][]*Interval) []*Interval {

    var tempSlice []*Interval

    for _, slice := range schedule {
        tempSlice = append(tempSlice, slice...)
    }

    sort.Slice(tempSlice, func(i, j int) bool {
        return tempSlice[i].Start < tempSlice[j].Start
    })

    return tempSlice
}