LeetCode 59 螺旋打印矩阵
class Solution:
def generateMatrix(self, n: int) -> List[List[int]]:
i = 0
j= 0
k = 0
t =1
d1 = 0
d2= 1
tb = [i for i in range(n)]
#print(tb)
a = [[0 for i in range(n)] for j in range(n)]
def getdir(d1,d2):
if [d1,d2]==[1,0]:
return 0,-1
elif [d1,d2] ==[0,1]:
return 1,0
elif [d1,d2] ==[-1,0]:
return 0,1
else:
return -1,0
while k<n**2:
a[i][j] = t
t+=1
if d1+i not in tb or d2+j not in tb or a[i+d1][j+d2]!=0:
d1,d2= getdir(d1,d2)
k+=1
#print(a)
i = i+d1
j+=d2
# print(d1,d2,i,j)
return a
leecode 56合并区间
特殊情况 输入长度为0的list
class Solution:
def merge(self, intervals: List[List[int]]) -> List[List[int]]:
new=[]
intervals.sort()
if len(intervals)==0:
return new
c =intervals[0]
for i in range(1,len(intervals)):
if intervals[i][0]>=c[0] and intervals[i][0]<=c[1]:
c[1] = max(c[1],intervals[i][1])
else:
new.append(c)
c = intervals[i]
new.append(c)
return new
Leetcode加油站：
class Solution:
def canCompleteCircuit(self, gas: List[int], cost: List[int]) -> int:
remain = [gas[i]-cost[i] for i in range(len(gas))]
for i in range(len(remain)):
if remain[i]<0:
continue
sum1 =0
t= i
k=0
while k<len(remain):
sum1 = sum1+remain[t]
t = t+1
if t>=len(remain):
t=0
k+=1
if sum1<0:
break
if sum1>=0 and k==len(remain):
return i
return -1