二进制搜索类：检索有序数组中最后一个元素的小问题

本文介绍了二进制搜索类：检索有序数组中最后一个元素的小问题的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 你好， 我有一个字符串数组，需要找到匹配的字符串和 最快的代码。我决定订购数组，然后写一个二进制的 搜索算法。 我想出的是以下内容。我注意到如果我设置： int upper = strings.GetUpperBound（0）; 我永远不会匹配数组中的最后一个元素（即iii） 如果我设置： int upper = strings.GetUpperBound（0）+ 1; 我也能匹配数组中的最后一个元素。 问题是我认为上层应该等于 strings.GetUpperBound（0）。 有什么我想念的吗？算法是错误的还是遗漏了什么??? 使用系统; 命名空间TestApplication { class BinarySearchClass { static void Main（string [] args） { string [] strings = new string [] {" aaa"，" bbb"，" ccc"，" ddd"，" eee"，" fff"， " ggg"， " hhh"，" iii"}; BinarySearchClass search = new BinarySearchClass（）; int res = search.FindString（字符串，iii）; Console.Read（）; } public int FindString （string [] strings，string str） { int lower = strings.GetLowerBound（0）; int upper = strings.GetUpperBound （0）; 返回this.BinarySearch（字符串，str，lower，upper）; } public int BinarySearch（string [] strings，string str，int lowerbound，int upper绑定） { int pos =（（上限 - 下限）/ 2）+下限; int res = string 。比较（字符串[pos]，str）; if（res 0） { pos = this.BinarySearch （strings，str，lowerbound，pos）; } else if（res< 0） { pos = this.BinarySearch（strings，str，pos，upperbound）; } 返回pos; } } } 问候， Bob Rock Hello, I have an array of strings and need to find the matching one with thefastest possible code. I decided to order the array and then write a binarysearch algo.What I came up with is the following. I noticed that if I set: int upper = strings.GetUpperBound(0); I never match the last element in the array (i.e. "iii") while if I set: int upper = strings.GetUpperBound(0) + 1; I''m able to match also the last element in the array.The problem is that I think upper should indeed be equal tostrings.GetUpperBound(0).Is there something I''m missing??? Is the algo wrong or missing something???using System; namespace TestApplication{class BinarySearchClass{static void Main(string[] args){string[] strings = new string[]{"aaa", "bbb", "ccc", "ddd", "eee", "fff","ggg", "hhh", "iii"}; BinarySearchClass search = new BinarySearchClass(); int res = search.FindString(strings, "iii"); Console.Read();} public int FindString(string[] strings, string str){int lower = strings.GetLowerBound(0);int upper = strings.GetUpperBound(0); return this.BinarySearch(strings, str, lower, upper);} public int BinarySearch(string[] strings, string str, int lowerbound, intupperbound){int pos = ((upperbound - lowerbound) / 2) + lowerbound; int res = string.Compare(strings[pos], str); if(res 0){pos = this.BinarySearch(strings, str, lowerbound, pos);}else if(res < 0){pos = this.BinarySearch(strings, str, pos, upperbound);}return pos;}}} Regards,Bob Rock 推荐答案 鲍勃，这个怎么样.. int pos = Array.BinarySearch< ; string>（字符串，" iii"）; JW Bob, how about this.. int pos= Array.BinarySearch<string>(strings, "iii"); J.W. 这篇关于二进制搜索类：检索有序数组中最后一个元素的小问题的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！