# PHP bubble sorting and binary searching for instances

Source: Internet
Author: User
We learned the bubble sort and binary search sort algorithms in junior high school. I will introduce the examples of the bubble sort and binary search in PHP.

We learned the bubble sort and binary search sort algorithms in junior high school. next I will introduce the PHP bubble sort and binary query examples.

Bubble sort to give a random array

\$ Arr = array (89,112,321,234 );

Statistics array:\$ Num = count (\$ arr );

Bubble sort in reverse order:

1. For (\$ I = 0; \$ I <\$ num-1; \$ I ++ ){
2. For (\$ m = 0; \$ m <\$ num-1; \$ m ++ ){
3. If (\$ arr [\$ m] <\$ arr [\$ m + 1]) {
4. \$ Temp = \$ arr [\$ m];
5. \$ Arr [\$ m] = \$ arr [\$ m + 1];
6. \$ Arr [\$ m + 1] = \$ temp;
7. }
8. // Echo \$ arr [\$ m].'
';
9. }
10. }
11. // Output the sorted result
12. Var_dump (\$ arr );
13. // Bubble sequence
14. For (\$ x = 0; \$ x <\$ num-1; \$ x ++ ){
15. For (\$ y = 0; \$ y <\$ num-1; \$ y ++ ){
16. If (\$ arr [\$ y]> \$ arr [\$ y + 1]) {
17. \$ Temp = \$ arr [\$ y];
18. \$ Arr [\$ y] = \$ arr [\$ y + 1];
19. \$ Arr [\$ y + 1] = \$ temp;
20. }
21. }
22. }
23. // Output the sorted result
24. Var_dump (\$ arr );
25. // Binary search
26. Function dichotomy (\$ array, \$ k, \$ low = 0, \$ high = 0 ){
27. If (count (\$ array )! = 0 & \$ high = 0 ){
28. \$ High = count (\$ array );
29. }
30. If (\$ low <= \$ high ){
31. \$ Mid = intval (\$ low + \$ high)/2 );
32. If (\$ array [\$ mid] === k ){
33. Return \$ mid;
34. } Elseif (\$ k <\$ array [\$ mid]) {
35. Return dichotomy (\$ array, \$ k, \$ low = 0, \$ mid-1 );
36. } Else {
37. Return dichotomy (\$ array, \$ k, \$ mid + 1, \$ high );
38. }
39. } Else {
40. Return false;
41. }
42. }
43. // Output the search result
44. Echo dichotomy (\$ arr, 23 );

Today, I briefly studied the most common sorting and binary lookup of the bubble method and wrote a simple case to enhance my learning of php, I also hope to provide some help to php learners in the future.

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