Lecture Notes on 18 Nov 2009

# Gets the combinations of size 'size'
def combine (a, b, idx, size):
  if (idx == len(a)):
    if (len(b) == size):
      print b
    return

  if (len(b) == size):
    print b
  else:
    c = b[:]
    b.append(a[idx])
    idx = idx + 1
    combine (a, c, idx, size)
    combine (a, b, idx, size)

def main ():
  a = [1, 2, 3, 4, 5]
  b = []
  combine (a, b, 0, 3)

main()
    
# Gets all combinations including the trivial combination with no elements
def combine (a, b, idx):
  if (idx == len(a)):
      print b
    return
  else:
    c = b[:]
    b.append(a[idx])
    idx = idx + 1
    combine (a, c, idx)
    combine (a, b, idx)

def main ():
  a = [1, 2, 3, 4, 5]
  b = []
  combine (a, b, 0)

main()
    
# Solution to Problem 5 in the Class Work for 18 Nov 2009
def combine (a, b, idx):
  if (idx == len(a)):
    sum = 0
    for num in b:
      sum = sum + num
    if (sum == 50):
      print b
      return
  else:
    c = b[:]
    b.append(a[idx])
    idx = idx + 1
    combine (a, b, idx)
    combine (a, c, idx)

def main():
  a = [15, 9, 30, 21, 19, 3, 12, 6, 25, 27]
  b = []
  combine (a, b, 0)

main()