Leetcode 0623

 

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