随笔分类 -  哈希表

摘要：题目：Given a string which contains only lowercase letters, remove duplicate letters so that every letter appear once and only once. You must make sure y... 阅读全文

摘要：题目：Given an array of citations (each citation is a non-negative integer) of a researcher, write a function to compute the researcher's h-index.Accordi... 阅读全文

摘要：题目：Given a pattern and a string str, find if str follows the same pattern.Here follow means a full match, such that there is a bijection between a let... 阅读全文

摘要：题目：You are playing the following Bulls and Cows game with your friend: You write a 4-digit secret number and ask your friend to guess it, each time yo... 阅读全文

摘要：题目：Given n points on a 2D plane, find the maximum number of points that lie on the same straight line.分析：固定一个点，遍历其余点，期间用一个HashMap记录两点斜率和斜率次数，求出局部最大值；然... 阅读全文

摘要：下面参考java.util.HashMap，写了一个简单的散列表，只实现了其中的put和get方法，使用链接法"碰撞冲突"。代码最后，自定义了一个People类，并覆盖了equals,hashCode,toString方法，实现了Comparable接口。利用People类检验散列表的正确性，并利用... 阅读全文

摘要：思路：只需遍历一次数组，利用HashMap保存数组元素和下标，如果target-数组元素存在HashMap的key中，则返回结果，如果不存在，则put到HashMap中，注意，这种遍历保证了数组的下标肯定不小于HashMap中的下标。Java代码： public int[] twoSum(in... 阅读全文