Java Algorithm Chapter Summary

1. Bubble sort

   Compare adjacent elements, if the first one is larger than the second, then swap their positions; each pair of adjacent elements is compared sequentially, and the last element should be the largest.

   int[] array = {10,13,12,8,11,6};// Array from small to large sort for  (int i = 0; i < array.length - 1; i++)  {     for (int j = 0; j < array.length - i -  1;j ++) {        if  (array[j] > array[j &NBSP;+&NBSP;1])  {            a =  Array[j];            array[j] = array[j &NBSP;+&NBSP;1];&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;ARRAY[J&NBSP;+&NBSP;1]  = a;        }    }}system.out.println ( Arrays.tostring (array));//[6, 8, 10, 11, 12, 13] 

3. Compare sort
   

   Take the elements in the array, followed by the elements, if they are greater than the subsequent elements, then the exchange of their position, in this way the array after comparison is a small to large sorted array.

   Array from small to large sort for (int i = 0; i < Array.Length; i++) {for (int j = i + 1; j < Array.length;j + +) {if (Array[i]            > Array[j]) {a = Array[i];            Array[i] = Array[j];        ARRAY[J] = A; }}}system.out.println (arrays.tostring (array));//[6, 8, 10, 11, 12, 13]

4. Recursive

   The way the function itself calls itself is called recursion.

   Public int[] sortarray (int[] array,int index) {    int a =  0;    if (index <= array.length - 1) {         for (int i = index + 1; i < array.length;i  ++) {            if (array[index] >  array[i]) {                 a = array[index];                 array[index] = array[i];                 array[i] = a;             }        }         sortarray (Array,index + 1);     }    return array;} System.out.println (Sortarray (array,0))

6. Two-point Search

   Two-point lookup speed, data sources need to arrange in order

   Query 11 in the array subscript int queryparam = 11;  Arrays.sort (array);//Sort int i = 0;int start = 0;int end = Array.length-1;while (start <= end) {i = (start + end)/    2;        if (Queryparam = = Array[i]) {System.out.println (i);    Break    } else if (Queryparam < array[i]) {end = i;    } else if (Queryparam > Array[i]) {start = i; }}

   
   

Java Algorithm Chapter Summary