java数据结构和算法------索引查找

  1 package iYou.neugle.search;

  2 

  3 import java.util.ArrayList;

  4 import java.util.List;

  5 

  6 public class Index_search {

  7     class IndexItem {

  8         public int index;

  9         public int start;

 10         public int length;

 11     }

 12 

 13     public int m = 100;

 14 

 15     public int[] table = new int[] { 101, 102, 103, 104, 105, 201, 202, 203,

 16             204, 301, 302, 303 };

 17 

 18     public List<IndexItem> indexTable = new ArrayList<Index_search.IndexItem>();

 19 

 20     public static void main(String[] args) {

 21         Index_search index = new Index_search();

 22         // 创建索引

 23         index.CreateIndex();

 24         // 向索引表中插入数据

 25         index.InsertIndex(205);

 26         // 利用索引表查找数据

 27         int result = index.SearchIndex(205);

 28         System.out.println("索引位置为" + result);

 29     }

 30 

 31     public void CreateIndex() {

 32         int[] type = new int[10000];

 33         int[] typeNum = new int[10000];

 34         for (int i = 0; i < this.table.length; i++) {

 35             int n = this.table[i] / m - 1;

 36             if (type[n] == 0) {

 37                 type[n] = 1;

 38             }

 39             typeNum[n]++;

 40         }

 41         int start = 0;

 42         for (int i = 0; i < typeNum.length; i++) {

 43             if (typeNum[i] == 0) {

 44                 break;

 45             }

 46             IndexItem item = new IndexItem();

 47             item.index = i;

 48             item.start = start;

 49             item.length = typeNum[i];

 50             indexTable.add(item);

 51             start += typeNum[i];

 52         }

 53     }

 54 

 55     public void InsertIndex(int key) {

 56         int n = key / m - 1;

 57         int index = -1;

 58         // 更新索引表

 59         for (int i = 0; i < this.indexTable.size(); i++) {

 60             if (n == this.indexTable.get(i).index) {

 61                 index = this.indexTable.get(i).start

 62                         + this.indexTable.get(i).length;

 63                 this.indexTable.get(i).length++;

 64                 break;

 65             }

 66         }

 67 

 68         for (int i = n + 1; i < this.indexTable.size(); i++) {

 69             this.indexTable.get(i).start++;

 70         }

 71 

 72         // 更新数组

 73         int[] temp = new int[this.table.length + 1];

 74         for (int i = 0; i < temp.length; i++) {

 75             if (i < index) {

 76                 temp[i] = this.table[i];

 77             } else if (i == index) {

 78                 temp[i] = key;

 79             } else {

 80                 temp[i] = this.table[i - 1];

 81             }

 82         }

 83 

 84         this.table = temp;

 85     }

 86 

 87     public int SearchIndex(int key) {

 88         int n = key / m - 1;

 89         int start = -1;

 90         int length = -1;

 91         // 找到索引位置

 92         for (int i = 0; i < this.indexTable.size(); i++) {

 93             if (n == this.indexTable.get(i).index) {

 94                 start = this.indexTable.get(i).start;

 95                 length = this.indexTable.get(i).length;

 96                 break;

 97             }

 98         }

 99 

100         if (start == -1) {

101             return -1;

102         }

103         // 从索引位置找数据

104         for (int i = start; i < start + length; i++) {

105             if (this.table[i] == key) {

106                 return i;

107             }

108         }

109         return -1;

110     }

111 }