[算法] 求无序数组元素最小差值

array = (5, 2, 4, 9, 0, 6)

# quick sort
# O(nlogn)
def split(list, start, end):
middle = list[end]
index = start -1
for i in range(start, end+1):
if list[i] <= middle:
index += 1
temp = list[i]
list[i] = list[index]
list[index] = temp

return index

def quick_sort(list, start, end):
if (start < end):
index = split(list, start, end)
quick_sort(list, start, index-1)
quick_sort(list, index+1, end)

# bucket sort
def bucket_sort(list):
max_e = list[0]
min_e = list[0]

# max & min element
for i in list:
if i > max_e:
max_e = i
if i < min_e:
min_e = i

bucket_v = max_e - min_e + 1
B = []
for i in range(bucket_v):
B.append(0)
for i in list:
B[i - min_e] += 1
return B

def min_diff():
l = list(array)

# sort
B = bucket_sort(l)
first = True
diff = -1
for i in range(len(B)):
if B[i] >= 2:
diff = 0
break
elif B[i] == 1 and first:
low = i
first = False
elif B[i] == 1: # ! first
high = i
tmp_diff = high - low
if (diff < 0 or tmp_diff < diff):
diff = tmp_diff
low = i
# else B[i] == 0, ignore

print "min diff from bucket sort:", diff

# qsort
quick_sort(l, 0, len(l)-1)
first = True
diff = -1
for i in l:
if first:
low = i
first = False
else:
high = i
tmp_diff = high - low
if (diff < 0 or tmp_diff < diff):
diff = tmp_diff
low = i

print "min diff from quick sort:", diff

if __name__ == "__main__":
print array
min_diff()