2b.go

2b.go

package main

import (
  "bufio"
  "os"
  "fmt"
  "sync"
  "strings"
  "strconv"
)

func validate(b string) (<-chan int) {
  r := make(chan int)
  go func(ns []string) {
    gt, leq := false, false
    defer close(r)
    for i := 0; i < len(ns) - 1; i++ {
      p, _ := strconv.Atoi(ns[i])
      q, _ := strconv.Atoi(ns[i+1])
      d := p - q
      if p > q {
	gt = gt || true
      } else {
	d = -d
	leq = leq || true
      }
      if d < 1 || d > 3 || (gt && leq) {
	r <- 0
	break
      }
    }
    r <- 1
  }(strings.Split(b, " "))
  return r
}

func main() {
  n, g := 0, sync.WaitGroup{}
  s, c := bufio.NewScanner(os.Stdin), make(chan int)
  for n = 0; s.Scan(); n++ {
    go func(line string) {
      c <- <-validate(line)
      g.Done()
    }(s.Text())
  }
  go func(n int) {
    g.Add(n)
    g.Wait()
    close(c)
  }(n)
  sum := 0
  for k := range(c) {
    sum += k
  }
  fmt.Printf("%d\n", sum)
}