non-overlapping-intervals.go

package problem0435

import (
	"github.com/aQuaYi/LeetCode-in-Go/kit"
	"sort"
)

type Interval = kit.Interval

func eraseOverlapIntervals(intervals []Interval) int {
    end := -1 << 31
    res:=0
    if len(intervals) == 1 {
        return 0
    }
    
    sort.Sort(B(intervals))
    
    for _,v := range intervals {
        if end <= v.Start  {
            end = v.End
        } else {
            res++
        }
    }

    return res
}

// B 经过排序后， End 小的排在前面
type B []Interval

func (a B) Len() int           { return len(a) }
func (a B) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
func (a B) Less(i, j int) bool { return a[i].End < a[j].End }