四平方和

import math
def f(n):
    if isinstance(n,int):
        for i in range(round(math.sqrt(n))):
            for j in range(round(math.sqrt(n))):
                for k in range(round(math.sqrt(n))):
                    h = math.sqrt(n - i*i - j*j - k*k)
                    # 剪掉使用了的值
                    if h == int(h):
                        print("(%d,%d,%d,%d)"%(i,j,k,h))
                        return 
    else:
        print("(0,0,0,0)")

f(5)
f(12)
f("aaa")