def generateMatrix(n):
matrix = [[0 for _ in xrange(n)] for _ in xrange(n)]
for (x, y), v in izip(spiral(True, 0, 0, n, n), count(1)):
matrix[y][x] = v
return matrix
def maxProfit(prices):
profit = 0
for previous, current in izip(prices[:-1],prices[1:]):
if current > previous:
profit += current - previous
return profit
def maxProfit(prices):
profit = 0
for previous, current in izip(prices[:-1], prices[1:]):
if current > previous:
profit += current - previous
return profit
def pow(x, n):
r = 1.0
if n < 0:
x = 1.0/x
n = -n
for a, b in izip(square(x), int2digits(n, 2)):
if b:
r *= a
return r
def convert(s, nRows):
if nRows == 1:
return s
n = nRows * 2 - 2
s += ' ' * (n - len(s) % n)
l = [s[i::n] for i in xrange(n)]
r = l[0]
for i in xrange(1, nRows - 1):
r += "".join(a + b for a, b in izip(l[i], l[n - i]))
r += l[nRows - 1]
return "".join(r.split(" "))
def convert(s, nRows):
if nRows == 1:
return s
n = nRows * 2 - 2
s += ' ' * (n - len(s) % n)
l = [s[i::n] for i in xrange(n)]
r = l[0]
for i in xrange(1, nRows-1):
r += "".join(a+b for a,b in izip(l[i], l[n-i]))
r += l[nRows-1]
return "".join(r.split(" "))
def canCompleteCircuit(gas, cost):
change = [(g-c) for g, c in izip(gas, cost)]
total = 0
stops = len(change)
l, r = 0, 0
while True:
while True:
total += change[r]
r = (r + 1) % stops
if total < 0:
break
if l == r:
return l
while total < 0:
total -= change[l]
l += 1
if l == stops:
return -1
def connect(root):
for level in iter_level([root]):
for a, b in izip(level, level[1:] + [None]):
a.next = b
def zigzagLevelOrder(root):
return [[node.val for node in v[::s]]
for v, s in izip(iter_level([root]), zigzag())]
def longestCommonPrefix(strs):
return "".join(c[0] for c in takewhile(lambda x: len(set(x))==1, izip(*strs)))
