二进制搜索Java实现算法

本文介绍了二进制搜索Java实现算法的处理方法，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

我需要实现二进制搜索算法帮助，可有人告诉我什么是错我的code：

公众诠释的bsearch（项目idToSearch）{     INT lowerBoundary = 0;     INT upperBoundary = myStore.size（） - 1;     INT中期= -1;     而（upperBoundary＆GT; = lowerBoundary）{         中期=（lowerBoundary + upperBoundary）/ 2;         //如果在中间的元素小于被搜索项，比设置为中等新下界         如果（myStore.get（中间）pareTo（idToSearch）℃，）{             lowerBoundary =中旬 - 1;         } 其他 {             upperBoundary =中等+ 1;         }     } //结束while循环     如果（myStore.get（中间）.equals（idToSearch））{         返回中旬;     } 其他 {         返回-1; //项目未找到     } } // end方法

解决方案

我想你犯了一个错误，当更新 lowerBoundary 和 upperBoundary 。

这可能是：

如果（myStore.get（MID）pareTo（idToSearch）小于0）{         lowerBoundary =中等+ 1;     } 其他 {         upperBoundary =中旬 - 1;     }

和你为什么不打破循环，如果你发现在元素中期？

I need help with implementing the binary search algorithm, can someone tell me what's wrong with my code:

public int bsearch(Item idToSearch) { int lowerBoundary = 0; int upperBoundary = myStore.size() - 1; int mid = -1; while(upperBoundary >= lowerBoundary) { mid = (lowerBoundary + upperBoundary) / 2; //if element at middle is less than item to be searched, than set new lower boundary to mid if(myStore.get(mid)pareTo(idToSearch) < 0) { lowerBoundary = mid - 1; } else { upperBoundary = mid + 1; } } //end while loop if(myStore.get(mid).equals(idToSearch)) { return mid; } else { return -1; // item not found } } // end method

解决方案

I think you made a mistake when update lowerBoundary and upperBoundary.

It may be:

if(myStore.get(mid)pareTo(idToSearch) < 0){ lowerBoundary = mid + 1; } else { upperBoundary = mid - 1; }

And why don't you break the loop if you find the element at mid?