交替打印 依次打印
https://mp.weixin.qq.com/s/I5va3PI1oGIj8R_n3Nw2yw
1115. 交替打印 FooBar - 力扣（LeetCode） https://leetcode.cn/problems/print-foobar-alternately/description/
func main() {
odd := make(chan struct{}, 1)
even := make(chan struct{}, 1)
odd <- struct{}{}
wg := sync.WaitGroup{}
wg.Add(2)
a := func() {
for i := 1; i <= 9; i += 2 {
<-odd
print(i, "\n")
even <- struct{}{}
}
wg.Done()
}
b := func() {
for i := 2; i <= 9; i += 2 {
<-even
print(i, "\n")
odd <- struct{}{}
}
wg.Done()
}
go a()
go b()
wg.Wait()
}
