A Powershell solution to the Johnny Hates Math problem on http://www.spoj.com/problems/ANARC07J/

JHM.ps1

function calc { 
  param (
    [String] $str, 
    [int] $target
  )
  foreach ($len in 1..5 ) {
    $firstStr = $str.SubString(0, $len)
    if ($firstStr.Length -lt $len) {
      break
    }
    if ($len -gt 1 -and $firstStr[0] -eq '0') {
      break
    }
    $first = [int] $firstStr
    $remTarget = $target - $first
    if ($remTarget -lt 0) {
      break
    }
    $remStr = $str.SubString($len)
    
    if ($remStr -eq '') {
      if ($remTarget -eq 0) {
        $str
      }
      break
    }
    
    foreach( $nextStr in @( calc $remStr $remTarget ) ) {
      if ($nextStr)
      {
        $firstStr + '+' + $nextStr
      }
    }
  }
}