Bulls and Cows solver, https://repl.it/repls/RelievedMonstrousFiles to run.

bulls_cows

ns = [1750, 1602, 3954, 4716]
ans = [(1, 1), (1, 1), (1, 1), (1, 1)]

def bc (a, b):
  bs = 0
  cs = 0
  for i1, i2 in zip(a, b):
    if i1 == i2:
      bs += 1
    elif i1 in b:
      cs += 1
  return bs, cs

def inner (a):
  for t, answer in zip(ns, ans):
    if bc([int (i) for i in list(str(n))], [int (i) for i in list(str(t))]) != answer:
      return
  print(n)

for n in range(10000):
  inner(n)