题解 | 小红的整数配对

package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
)

func main() {
	buf := bufio.NewReader(os.Stdin)
	var n, k int
	fmt.Fscan(buf, &n, &k)
	sli := make([]int, n)
	for i := 0; i < n; i++ {
		fmt.Fscan(buf, &sli[i])
	}
	sort.Slice(sli, func(i, j int) bool {
		return sli[i] > sli[j]
	})
	count := 0
	for i := 0; i < n-1; i++ {
		if sli[i]-sli[i+1] > k {
			continue
		} else {
			count += sli[i] * sli[i+1]
			i++
		}
	}
	fmt.Print(count)
}