Generate combinations from a pool of elements

comb.py

#!/ucrt64/bin/python
from typing import List
from sys import argv

# eg. pool = ['0', '1']
# n = 3
# total count = 2 ** 3 = 8
# 0 0 0
# 0 0 1
# 0 1 0
# 0 1 1
# 1 0 0
# 1 0 1
# 1 1 0
# 1 1 1

pool: List[str] = ['🥵', '🤢', '🥶']

def getCombinations(n: int) -> List[str]:
        res: List[str] = []
        def dfs(s: str) -> None:
                if len(s) == n:
                        res.append(s)
                        return
                for item in pool:
                        dfs(s + item)
        dfs("")
        return res

def getCombinationsIterative(n: int) -> List[str]:
        res: List[str] = []
        stack: List[str] = [""]
        while stack:
                s = stack.pop()
                if len(s) == n:
                        res.append(s)
                        continue
                for item in reversed(pool):
                        stack.append(s + item)
        return res

def isInt(s: str) -> bool:
        if not s:
                return False
        try:
                int(s)
                return True
        except ValueError:
                return False

if __name__ == "__main__":
        if len(argv) != 2 or not isInt(argv[1]):
                print("Usage: comb [number]")
                exit(1)
        n = int(argv[1])
        totalCount = len(pool) ** n
        result = getCombinationsIterative(n)
        for i, s in enumerate(result):
                # spaces are added as paddings
                print(str(i) + " " * (1 + len(str(totalCount)) - len(str(i))) + s)
        print("Generated " + str(totalCount) + " combinations of length " + argv[1])

Usage

comb.py [number]

Example

$ ./comb.py 3
0  🥵🥵🥵
1  🥵🥵🤢
2  🥵🥵🥶
3  🥵🤢🥵
4  🥵🤢🤢
5  🥵🤢🥶
6  🥵🥶🥵
7  🥵🥶🤢
8  🥵🥶🥶
9  🤢🥵🥵
10 🤢🥵🤢
11 🤢🥵🥶
12 🤢🤢🥵
13 🤢🤢🤢
14 🤢🤢🥶
15 🤢🥶🥵
16 🤢🥶🤢
17 🤢🥶🥶
18 🥶🥵🥵
19 🥶🥵🤢
20 🥶🥵🥶
21 🥶🤢🥵
22 🥶🤢🤢
23 🥶🤢🥶
24 🥶🥶🥵
25 🥶🥶🤢
26 🥶🥶🥶
Generated 27 combinations of length 3