func RandomListByWeights(weights []int, nums int, repeat bool) (randomItemList []int) {
common.Assert(nums >= 1, "random num must no less than 1")
if !repeat {
common.Assert(nums <= len(weights), "random nums should no more than item list length")
}
randomItemList = make([]int, 0)
tempWeights := make([]int, len(weights))
totalWeights := 0
for i, weight := range weights {
common.Assert(weight >= 0, "weight should no less than 0")
totalWeights += weight
tempWeights[i] = weight
}
for i := 0; i < nums; i++ {
common.Assert(totalWeights > 0, "total weights should be more than 0")
rand.Seed(time.Now().UnixNano())
randNum := rand.Intn(totalWeights)
for weightIndex, weight := range tempWeights {
if randNum >= weight {
randNum -= weight
continue
}
randomItemList = append(randomItemList, weightIndex)
if !repeat {
totalWeights -= weight
tempWeights[weightIndex] = 0
}
break
}
}
return
}
func RandBetween(min int, max int) (num int) {
common.Assert(min < max, "min should less than max")
diff := max - min
num = rand.Intn(diff)
return
}