math_util.go

package gotha

import (
	"bytes"
	"math/rand"
	"time"
)

func max(a int, b int) int {
	if a > b {
		return a
	}
	return b
}

func min(a int, b int) int {
	if a < b {
		return a
	}
	return b
}

func abs(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

func abs64(a int64) int64 {
	if a < 0 {
		return -a
	}
	return a
}

func rankFromRating(rating int) int {
	rk := (rating+950)/100 - 30
	if rk > 8 {
		rk = 8
	}
	if rk < -30 {
		rk = -30
	}
	return rk
}

func RandChar(size int) string {
	char := "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
	rand.NewSource(time.Now().UnixNano()) // 产生随机种子
	var s bytes.Buffer
	for i := 0; i < size; i++ {
		s.WriteByte(char[rand.Int63()%int64(len(char))])
	}
	return s.String()
}