qsort.go

package main

import (
	"fmt"
)

var arr []int = []int{
	1350, 1446, 1021, 1328, 1170, 1566, 1588, 1444, 1341, 1311,
	1610, 1506, 1530, 1637, 1620, 1390, 1013, 1489, 1058, 1310,
	1266, 1150, 1232, 1309, 1179, 953, 1553, 1240, 1319, 1029,
	1479, 1226, 1053, 1221, 1249, 1108, 1506, 1368, 1126, 1338,
	1045, 1058, 1249, 1535, 1497, 1248, 1292, 1554, 1026, 1510,
	1303, 1596, 1065, 995, 1434, 1311, 1659, 1501, 1502, 1296,
	1135, 1653, 1525, 1131, 1021, 1202, 1486, 1587, 1559, 1420,
	1560, 1246, 1113, 1573, 1002, 1031, 1370, 1545, 1383, 1430,
	1630, 950, 1451, 1373, 1468, 1545, 1502, 1145, 1123, 1566,
	1403, 1192, 1186, 970, 1286, 1518, 1303, 1652, 1016, 1265,
	976, 1203, 1580, 1596, 1256, 1037, 991, 1026, 1163, 1225,
	1202, 1193, 1075, 1339, 1338, 1469, 1100, 1360, 960, 1400,
	1413, 1276, 1601, 1559, 1154, 1212, 1124, 1363, 1508, 1573,
	1647, 1081, 1225, 1190, 1370, 986, 1341, 1067, 1460, 1010,
	1534, 1535, 1090,
}

func swap(i, j int) {
	c := arr[i]
	arr[i] = arr[j]
	arr[j] = c
}
func less(i, j int) bool {
	if arr[i] < arr[j] {
		return true
	} else {
		return false
	}

}
func qsort(n int,
	less func(i, j int) bool,
	swap func(i, j int), optional_m ...int) {
	m := 0
	if len(optional_m) > 0 {
		m = optional_m[0]
	}
	if m > n-1 {
		return
	}
	f := m
	p := n - 1
	cp := p
	for j := f; j < p; j++ {
		if less(j, cp) {
			if j == cp {
				cp = f
			} else if f == cp {
				cp = j
			}
			swap(j, f)
			f++
		}
	}
	swap(f, p)
	qsort(f, less, swap, m)
	qsort(n, less, swap, f+1)

}
func main() {
	qsort(len(arr), less, swap)
	fmt.Println(arr)

}