Find minimum swaps to order a string of 0's and 1's

gistfile1.rb

def findOperations(string)
  operations = 0
  list = string.split("")
  startIndex = 0
  endIndex = list.length-1
  while startIndex < endIndex
      if list[endIndex]=="0"
        if list[startIndex] == "1"
          list[startIndex], list[endIndex] = list[endIndex], list[startIndex]
          operations = operations+1
          endIndex-=1
        end
        startIndex+=1
      else
        endIndex-=1
      end
  end
  operations
end

input = gets
returnValue = findOperations(input)
puts returnValue