My solutions for the 2013 hacker cup qualification round in Go. My original solution for balanced smiles is broken but i'm gonna fix it

balancedsmiles.go

package main

import (
  "fmt"
  "os"
  "io/ioutil"
  "strings"
  "strconv"
  "./stack"
)

func main() {
  filename := os.Args[1]
  bContents,_ := ioutil.ReadFile(filename)
  sContents := string(bContents)
  aContents := strings.Split(sContents,"\n")
  caseNum,_ := strconv.Atoi(aContents[0])

  for cn,s := range aContents[1:caseNum + 1] {
    result := "YES"
    stack := new(stack.Stack)
    wasCollon := false
    for _,char := range s {
      if char >= 'a' && char <= 'z' || char == ' ' {
        continue
      }
      if char == ':' {
        wasCollon = true
        continue
      }
      if char == '(' {
        if wasCollon {
          wasCollon = false
          continue
        } else {
          stack.Push(char)
        }
      }
      if char == ')' {
        if stack.Top() == '(' {
          stack.Pop()
        } else if wasCollon {
          wasCollon = false
          continue
        } else {
          result = "NO"
        }
      }
    }
  if (stack.Top() != nil) {
    result = "NO"
  }
  fmt.Printf("Case #%d: %s\n", cn + 1, result)
  }
}

beautifulstrings.go

package main

import (
  "fmt"
  "os"
  "io/ioutil"
  "strings"
  "strconv"
  "regexp"
  "sort"
)

var puncRegex = regexp.MustCompile("[^A-Za-z0-9\n]+")

type ValSorter struct {
  Keys []rune
  Vals []int
}

func NewValSorter(m map[rune]int) *ValSorter {
  vs := &ValSorter{
    Keys: make([]rune, 0, len(m)),
    Vals: make([]int, 0, len(m)),
  }
  for k, v := range m {
    vs.Keys = append(vs.Keys, k)
    vs.Vals = append(vs.Vals, v)
  }
  return vs
}

func (vs *ValSorter) Sort() {
  sort.Sort(vs)
}

func (vs *ValSorter) Len() int           { return len(vs.Vals) }
func (vs *ValSorter) Less(i, j int) bool { return vs.Vals[i] > vs.Vals[j] }
func (vs *ValSorter) Swap(i, j int) {
  vs.Vals[i], vs.Vals[j] = vs.Vals[j], vs.Vals[i]
  vs.Keys[i], vs.Keys[j] = vs.Keys[j], vs.Keys[i]
}

func main () {
  filename := os.Args[1]
  bContents,_ := ioutil.ReadFile(filename)
  sContents := strings.ToLower(string(bContents))
  sContents = puncRegex.ReplaceAllString(sContents,"")
  aContents := strings.Split(sContents,"\n")
  caseNum,_ := strconv.Atoi(aContents[0])

  for cn,s := range aContents[1:caseNum + 1] {
    tokens := make(map[rune]int)
    for _,char := range s {
      tokens[char] = tokens[char] + 1
    }
    vs := NewValSorter(tokens)
    vs.Sort()
    weight := 26
    sum := 0
    for i := 0; i < vs.Len(); i++ {
      sum = sum + weight * vs.Vals[i]
      weight--
    }
    fmt.Printf("Case #%d: %d\n", cn + 1, sum)
  }

}