负数+0+正数

一堆负数+一堆0+一堆正数
找最后一个出现的负数和第一个出现的正数的下标 下标从1开始
果然没运行看不出哪里错了 555

def findnum(nums):
    res = []
    for i in range(len(nums)):
        # 如果全是0 边界
        if nums[0] == 0 and nums[-1] == 0:
            return 0, 0
        # 记录0的下标
        elif nums[i] == 0:
            # 因为数字从下标1开始
            res.append(i + 1)
        elif nums[i] > 0:# 找到正数跳出循环
            break
    print(res)
    return res[0] - 1, res[-1] + 1


nums = [-3, -4, -1, 0, 0, 0, 0, 1, 2, 3, 6]
print(findnum(nums))

nums = [0, 0, 0, 0, 1, 2, 3, 6]
print(findnum(nums))

nums = [0, 0, 0, 0]
print(findnum(nums))

二分 找第一个0和最后一个0的位置 然后他们前面各一位就是要找的下标

class Solution():
    def find_left(self, nums):
        l = 0
        r = len(nums) - 1
        while l <= r:
            mid = (l + r) // 2
            if nums[mid] == 0:
                r = mid - 1
            elif nums[mid] > 0:
                r = mid - 1
            else:
                l = mid + 1
        # 第一个0,l>right = mid -1 l=mid
        # 下标从1开始
        return l + 1

    def find_right(self, nums):
        l = 0
        r = len(nums) - 1
        while l <= r:
            mid = (l + r) // 2
            if nums[mid] == 0:
                l = mid + 1
            elif nums[mid] < 0:
                l = mid + 1
            else:
                r = mid - 1
        # 最后一个0,l = mid+1 r=mid
        # 下标从1开始
        return r + 1

    def find_num(self, nums):
        if not nums or nums[0] == 0 and nums[-1] == 0:
            return 0, 0
        ll = self.find_left(nums)
        rr = self.find_right(nums)
        return ll - 1, rr + 1


nums = [-3, -4, -1, 0, 0, 0, 0, 1, 2, 3, 6]
s = Solution()
print(s.find_num(nums))


nums = [0, 0, 0, 0, 1, 2, 3, 6]
print(s.find_num(nums))

nums = [0, 0, 0, 0]
print(s.find_num(nums))