>When no more interesting kata can be resolved, I just choose to create the new kata, to solve their own, to enjoy the process  --myjinxin2015 said

# Description:
 Give you two number `m` and `n`(two positive integer, m < n), make a triangle pattern with number sequence `m to n`. The order is clockwise, starting from the top corner, like this:
 
```
 When m=1 n=10  triangle is:
    1
   9 2
  8 0 3
 7 6 5 4
```
 Note: The pattern only uses the last digit of each number; Each row separated by "\n"; Each digit separated by a space; Left side may need pad some spaces, but don't pad the right side; If `m to n` can not make the triangle, return `""`.
  
# Some examples:

```
makeTriangle(1,3) should return:
 1
3 2

makeTriangle(6,20) should return: 

    6
   7 7
  6 8 8
 5 0 9 9
4 3 2 1 0

makeTriangle(1,12) should return ""
 
```

```python

USER_FILENAME = "<user_code>"
import sys, json, builtins
import math, heapq, bisect, itertools, functools, collections, statistics, fractions, decimal, operator, array, random, re, string, os, pathlib
try:
    import resource as _res
except Exception:
    _res = None
from collections import Counter, defaultdict, deque, OrderedDict
from functools import lru_cache, reduce
from itertools import accumulate, permutations, combinations, product
from math import gcd, ceil, floor, sqrt
from decimal import Decimal
try:
    from typing import *
except Exception:
    pass
try:
    sys.setrecursionlimit(1_000_000)
except Exception:
    pass
try:
    import site as _site
    try:
        _sys_sites = _site.getsitepackages() if hasattr(_site, "getsitepackages") else []
        for _p in _sys_sites:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
    try:
        _usp = _site.getusersitepackages()
        if isinstance(_usp, str):
            _usp = [_usp]
        for _p in _usp:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
except Exception:
    pass

def _disabled_input(*args, **kwargs):
    raise RuntimeError("input() is disabled in callable mode")
builtins.input = _disabled_input

ns = {"__name__": "__judge__"}  # prevent if __name__ == "__main__" blocks
for _k, _v in list(globals().items()):
    if not _k.startswith("_"):
        ns[_k] = _v
_CODE = 'def make_triangle(m, n):\n    """\n    makeTriangle produces a ∆ in a special sequence of numbers.\n    m is the starting point and n is the finishibg one.\n    The final digit of each number is taken as a character in making the ∆.\n    This functions returns a ∆ as a string if possible with the given input else, returns an empty string.\n    """\n\n    #Type check for arguments\n    if (type(m)!=type(0)) or (type(n)!=type(0)):\n        raise TypeError("m and n should be int")\n    #Value check for arguments\n    if m >= n:\n        raise ValueError("m not < n")\n\n    chars = [str(i)[-1] for i in range(m, n+1)]\n    #chars contains all the characters that will make up the ∆.\n    \n    #Can this set of chars make a ∆.\n    row, charc = 0, 0 #ncpr is the no. of rows in a ∆. And charc is the no. of characters a ∆ of specific side length contains. Both initially set to 0.\n\n    while True:\n        #The loop will break if the ∆ is possible else, will cause the function to return an empty string.\n        row += 1; charc = 0\n        for j in range(1, row): charc += j\n        if len(chars) == charc: row -= 1; break\n        if len(chars) < charc: return \'\'\n    \n    #∆ generation\n    lor = [[\' \' for j in range(i)] for i in range(1, row+1)] #lor contains all the rows of the ∆ as white strings.\n    #For Step-1 to work\n    i1,sp, b = 0, 0, -1\n    #For Step-2 to work\n    c = 2\n    i2, l = row-c, 0\n    #For Step-3 to work\n    i3, j= row-2, 0\n    while True: \n        if len(chars)==0: break\n        #Step-1\n        while i1 <= row-1:\n            lor[i1][b] = chars[0]\n            chars.pop(0)\n            i1 += 1\n        i1 = sp+2; b -= 1\n        if len(chars)==0: break\n        #Step-2\n        while i2 >= l:\n            lor[row-1][i2] = chars[0]\n            chars.pop(0)\n            i2 -= 1\n        row -= 1; c += 1; i2 = row-c; l += 1\n        if len(chars)==0: break\n        #Step-3\n        while i3 > sp:\n            lor[i3][j] = chars[0]\n            chars.pop(0)\n            i3 -= 1\n        i3 = row-2; j += 1; sp += 2\n    l = \'\'\n    for i in lor:\n        if i==lor[0]:\n            l += \' \'*(len(lor)-len(i))+i[0]+\'\\n\'\n            continue\n        for j in range(len(i)):\n            if j==0:\n                l += \' \'*(len(lor)-len(i))+i[j]+\' \'\n            elif j==len(i)-1:\n                l += i[j]\n            else:\n                l += i[j]+\' \'\n        if i!=lor[-1]:\n            l += \'\\n\'\n    return l'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'make_triangle'
if _fn_name:
    if "Solution" in ns:
        try:
            _obj = ns["Solution"]()
            if hasattr(_obj, _fn_name):
                _target = getattr(_obj, _fn_name)
        except Exception:
            _target = None
    if _target is None and _fn_name in ns and callable(ns[_fn_name]):
        _target = ns[_fn_name]
# Fallback: if there's exactly one user-defined function, use it
if _target is None:
    _cands = [v for k, v in ns.items() if callable(v) and getattr(v, "__module__", "") in ("__judge__", "__main__")]
    _user_funcs = [c for c in _cands if getattr(c, "__name__", "").startswith("_") is False]
    if len(_user_funcs) == 1:
        _target = _user_funcs[0]
if _target is None:
    raise RuntimeError(f"Could not resolve callable '{_fn_name}'")

_raw = sys.stdin.read().strip()
if _raw:
    _parsed = json.loads(_raw)
    if isinstance(_parsed, dict):
        _kwargs = _parsed.get("kwargs", {})
        _args = _parsed.get("args", [])
    else:
        _args, _kwargs = _parsed, {}
else:
    _args, _kwargs = [], {}
if not isinstance(_args, (list, tuple)):
    _args = [_args]
_res = _target(*_args, **_kwargs)
try:
    sys.stdout.write(repr(_res) + "\n")
except Exception:
    pass

```

Measured memory_bytes: 7005