国庆比较闲，复习一下算法，随便练练objective-c；
本文采用objective-c实现常见的排序算法：选择排序，插入排序，快速排序。
悼念乔帮主，期待apple在后乔帮主时代创造出更出色的产品。
1 //
2 // Sort.h
3 // Algorithm
4 //
5 // Created by 张 汉国 on 11-9-30.
6 // Copyright 2011年 __MyCompanyName__. All rights reserved.
7 //
8
9 #import <Foundation/Foundation.h>
10
11 @interface Sort : NSObject{
12
13 }
14
15 //选择排序
16 -(void)selectSortWithArray:(NSArray *)aData;
17 //插入排序
18 -(void)insertSortWithArray:(NSArray *)aData;
19 //快速排序
20 -(void)quickSortWithArray:(NSArray *)aData;
21
22 -(void)swapWithData:(NSMutableArray *)aData index1:(NSInteger)index1 index2:(NSInteger)index2;
23
24
25 @end
1 //
2 // Sort.m
3 // Algorithm
4 //
5 // Created by 张 汉国 on 11-9-30.
6 // Copyright 2011年 __MyCompanyName__. All rights reserved.
7 //
8
9 #import "Sort.h"
10
11 @interface Sort()
12 -(void)quickSortWithArray:(NSArray *)aData left:(NSInteger)left right:(NSInteger)right;
13 @end
14
15 @implementation Sort
16
17 - (id)init
18 {
19 self = [super init];
20 if (self) {
21 // Initialization code here.
22 }
23
24 return self;
25 }
26
27 -(void)selectSortWithArray:(NSArray *)aData{
28 NSMutableArray *data = [[NSMutableArray alloc]initWithArray:aData];
29 for (int i=0; i<[data count]-1; i++) {
30 int m =i;
31 for (int j =i+1; j<[data count]; j++) {
32 if ([data objectAtIndex:j] < [data objectAtIndex:m]) {
33 m = j;
34 }
35 }
36 if (m != i) {
37 [self swapWithData:data index1:m index2:i];
38 }
39 }
40 NSLog(@"选择排序后的结果：%@",[data description]);
41 [data release];
42 }
43
44 -(void)insertSortWithArray:(NSArray *)aData{
45 NSMutableArray *data = [[NSMutableArray alloc]initWithArray:aData];
46 for (int i = 1; i < [data count]; i++) {
47 id tmp = [data objectAtIndex:i];
48 int j = i-1;
49 while (j != -1 && [data objectAtIndex:j] > tmp) {
50 [data replaceObjectAtIndex:j+1 withObject:[data objectAtIndex:j]];
51 j--;
52 }
53 [data replaceObjectAtIndex:j+1 withObject:tmp];
54 }
55 NSLog(@"插入排序后的结果：%@",[data description]);
56 [data release];
57 }
58
59 -(void)quickSortWithArray:(NSArray *)aData{
60 NSMutableArray *data = [[NSMutableArray alloc] initWithArray:aData];
61 [self quickSortWithArray:data left:0 right:[aData count]-1];
62 NSLog(@"快速排序后的结果：%@",[data description]);
63 [data release];
64
65 }
66
67 -(void)quickSortWithArray:(NSMutableArray *)aData left:(NSInteger)left right:(NSInteger)right{
68 if (right > left) {
69 NSInteger i = left;
70 NSInteger j = right + 1;
71 while (true) {
72 while (i+1 < [aData count] && [aData objectAtIndex:++i] < [aData objectAtIndex:left]) ;
73 while (j-1 > -1 && [aData objectAtIndex:--j] > [aData objectAtIndex:left]) ;
74 if (i >= j) {
75 break;
76 }
77 [self swapWithData:aData index1:i index2:j];
78 }
79 [self swapWithData:aData index1:left index2:j];
80 [self quickSortWithArray:aData left:left right:j-1];
81 [self quickSortWithArray:aData left:j+1 right:right];
82 }
83 }
84
85
86 -(void)dealloc{
87 [super dealloc];
88 }
89
90 -(void)swapWithData:(NSMutableArray *)aData index1:(NSInteger)index1 index2:(NSInteger)index2{
91 NSNumber *tmp = [aData objectAtIndex:index1];
92 [aData replaceObjectAtIndex:index1 withObject:[aData objectAtIndex:index2]];
93 [aData replaceObjectAtIndex:index2 withObject:tmp];
94 }
95
96 @end
测试例子：
1 //
2 // main.m
3 // Algorithm
4 //
5 // Created by 张 汉国 on 11-9-30.
6 // Copyright 2011年 __MyCompanyName__. All rights reserved.
7 //
8
9 #import <Foundation/Foundation.h>
10 #import "Sort.h"
11
12 #define kSize 20
13 #define kMax 100
14
15 int main (int argc, const char * argv[])
16 {
17
18 NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
19
20 // insert code here...
21 NSLog(@"Hello, World!");
22
23 NSMutableArray *data = [[NSMutableArray alloc] initWithCapacity:kSize];
24
25 for (int i =0;i<kSize;i++) {
26 u_int32_t x = arc4random() % kMax;//0~kMax
27 NSNumber *num = [[NSNumber alloc] initWithInt:x];
28 [data addObject:num];
29 [num release];
30 }
31
32 NSLog(@"排序前的数据：%@",[data description]);
33
34 Sort *sort = [[Sort alloc] init];
35 [sort selectSortWithArray:data];
36 [sort insertSortWithArray:data];
37 [sort quickSortWithArray:data];
38 [sort release];
39 [data release];
40 [pool drain];
41 return 0;
42 }