leetcode-go/written-exam/tencent-2017-summer/cal-diff.go

package main

import (
	"fmt"
	"math"
	"sort"
)

type ints [][2]int

func (is ints) Len() int           { return len(is) }
func (is ints) Less(i, j int) bool { return is[i][0] < is[j][0] }
func (is ints) Swap(i, j int)      { is[i], is[j] = is[j], is[i] }

func main() {
	var N int
	_, err := fmt.Scan(&N)
	for err != nil {
		m := make(map[int]int)
		for i, v := 0, 0; i < N; i++ {
			fmt.Scan(&v)
			m[v]++
		}
		nums := make([][2]int, 0)
		for k, v := range m {
			nums = append(nums, [2]int{k, v})
		}
		sort.Sort(ints(nums))
		min, minCnt := math.MaxInt32, 0
		for i := range nums {
			if 1 < nums[i][1] {
				if 0 < min {
					min = 0
					minCnt = nums[i][1] * (nums[i][1] - 1) / 2
				} else {
					minCnt += nums[i][1] * (nums[i][1] - 1) / 2
				}
			} else if 0 < i {
				if det := nums[i][0] - nums[i-1][0]; det < min {
					min = det
					minCnt = nums[i][1] * nums[i-1][1]
				} else if det == min {
					minCnt += nums[i][1] * nums[i-1][1]
				}
			}
		}
		var maxCnt int
		l := len(nums)
		if l == 1 {
			maxCnt = nums[0][1] * (nums[0][1] - 1) / 2
		} else {
			maxCnt = nums[0][1] * nums[l-1][1]
		}
		fmt.Printf("%d %d\n", minCnt, maxCnt)
		_, err = fmt.Scan(&N)
	}
}