1.  String to Integer (atoi) Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input cases. Notes: It is inte…

LeetCode:Best Time to Buy and Sell Stock Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted to complete at most one transaction (ie, buy one and sell one share of the stock), design an a…

Best Time to Buy and Sell Stock I 题目链接 题目要求: Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted to complete at most one transaction (ie, buy one and sell one share of the stock), design…

题记:在求最大最小值的类似题目中,递推思想的奇妙之处,在于递推过程也就是比较求值的过程,从而做到一次遍历得到结果. LeetCode 上面的这三道题最能展现递推思想的美丽之处了. 题1 Best Time to Buy and Sell Stock Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted to complet…

Best Time to Buy and Sell Stock Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted to complete at most one transaction (ie, buy one and sell one share of the stock), design an algorithm…

Best Time to Buy and Sell Stock I 你只能一个操作:维修preMin拍摄前最少发生值 代码例如以下: int maxProfit(vector<int> &prices) { if (prices.size() == 0) return 0; int profit = 0; int preMin = prices[0]; for (int i = 1; i < prices.size(); i++) { if (prices[i] < pre…

Leetcode 8. String to Integer (atoi) atoi函数实现 (字符串) 题目描述 实现atoi函数,将一个字符串转化为数字 测试样例 Input: "42" Output: 42 Input: " -42" Output: -42 Input: "4193 with words" Output: 4193 Input: "words and 987" Output: 0 详细分析 这道题的cor…

String to Integer (atoi) Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input cases. Notes: It is intended f…

实现字符串转整形数字 遵循几个规则: 1. 函数首先丢弃尽可能多的空格字符,直到找到第一个非空格字符. 2. 此时取初始加号或减号. 3. 后面跟着尽可能多的数字,并将它们解释为一个数值. 4. 字符串可以在组成整数的字符之后包含其他字符,这些字符将被忽略,并且对该函数的行为没有影响. 5. 如果str中的第一个非空格字符序列不是有效的整数,则为0. Runtime: 16 ms, faster than 62.80% of C++ online submissions for String t…

8. String to Integer (atoi) Medium Implement atoi which converts a string to an integer. The function first discards as many whitespace characters as necessary until the first non-whitespace character is found. Then, starting from this character, tak…