66 plus one
用digit这个数组代表数值,要将此数加一,carry=1时代表需要进位,要在数组最左边插入一个1
class Solution: def plusOne(self, digits): len_s = len(digits) carry = 1 for i in range(len_s - 1, -1, -1): total = digits[i] + carry digit = int(total % 10) carry = int(total / 10) digits[i] = digit if 1 == carry: digits.insert(0, 1) return digits
167.two sum || input array is sorted
要找到满足两个数,他们的和等于target,返回他们在数组中的下标,可以选择类似夹逼的思想,左右两边都进行逼近,如果两数之和小于target,就将左边的数向右移一个,大于target则将右边的数向左移一个
class Solution(object): def twoSum(self, numbers, target): left, right = 0, len(numbers) - 1 while left < right: if numbers[left] + numbers[right] == target: return [left + 1, right + 1] elif numbers[left] + numbers[right] > target: right -= 1 else: left += 1