Sokoban Solver

sokoban-solver.groovy

def originalNumbers = [6,3,5,4,2]
def ops = ['x', '-', '-', '+']
def target = 21

def combine(a, b, op) {
   if(op == '+') {
      return a + b
   }
   else if (op == '-') {
      return a - b
   }
   else {
      return a * b
   }
}
def currentRouteResult = -1
def route
while(currentRouteResult != target) {
    route = []
    def numbersOnThisRoute = originalNumbers.clone()
    def opsForThisRoute = ops.clone()

    while(opsForThisRoute.size() && numbersOnThisRoute.size() > 1) {
       //println "State ::: ops are ${opsForThisRoute}, numbers are ${numbersOnThisRoute}"
       Collections.shuffle(opsForThisRoute)
       Collections.shuffle(numbersOnThisRoute)
       def op = opsForThisRoute.pop()
       def a = numbersOnThisRoute.pop()
       def b = numbersOnThisRoute.pop()
       def newNumber = combine(a, b, op)
       numbersOnThisRoute.push(newNumber)
       //println "Applying op ${a} ${op} ${b}"
       route << "${a}${op}${b} (${newNumber})".toString()
    }
   //println "State ::: ops are ${opsForThisRoute}, numbers are ${numbersOnThisRoute}"
   if(numbersOnThisRoute.size() == 1) {
       currentRouteResult = numbersOnThisRoute[0]
   }
}
println "We got to ${target} by doing ${route.join(', ')}"