classSolution:def_init_(self):pass# 防止無效輸入defvalid_check(self, a):if len(a) == 0:
returnFalsefor i in range(len(a)):
if a[i] < 0or a[i] > len(a) - 1:
returnFalsereturnTruedefMethod_1(self, a):if valid_check(a):
a = sorted(a)
for i in range(len(a) - 1):
if a[i] == a[i + 1]:
return a[i]
else: returnFalsedefMethod_2(self, a):if valid_check(a):
num_array = np.zeros(len(a))
for i in range(len(a)):
if num_array[a[i]] == 0:
num_array[a[i]] += 1else:
return a[i]
else: returnFalsedefMethod_3(self, a):if valid_check(a):
for i in range(len(a)):
while a[i] != i:
if a[a[i]] == a[i]:
return a[i]
else:
a[a[i]], a[i] = a[i], a[a[i]]
else: returnFalse