数组排序

 1 #pragma mark 冒泡排序
 2 - (void)userArrSort:(NSMutableArray *)userArr
 3 {
 4     int n = userArr.count;
 5     int i,j;
 6     NSDictionary *temp;
 7     for(j=0;j<n-1;j++)
 8     {
 9         for(i=0;i<n-1-j;i++)
10         {
11 //            NSDictionary*ssy = [];
12             if(((NSString *)[userArr[i] objectForKey:@"vlevel"]).intValue<((NSString *)[userArr[i+1] objectForKey:@"vlevel"]).intValue)//数组元素大小按升序排列
13             {
14                 temp=userArr[i];
15                 userArr[i]=userArr[i+1];
16                 userArr[i+1]=temp;
17             }
18         }
19     }
20     for (int x = 0; x<userArr.count; x++)
21     {
22         if (1) {
23 //            [userArr replaceObjectAtIndex:0 withObject:[userArr[i]];
24         }
25     }
26 }
27 #pragma mark 已排序数组插入一条数据
28 - (void)insertObjectInUserArr:(NSMutableArray *)userArr withobject:(NSDictionary *)dic
29 {
30     int j;
31     if(((NSString *)[dic objectForKey:@"vlevel"]).intValue<=((NSString *)[userArr[userArr.count - 1] objectForKey:@"vlevel"]).intValue)
32     {
33         [userArr insertObject:dic atIndex:userArr.count];
34     }else
35     {
36         for(int i=0;i<userArr.count;i++)
37         {
38             if(((NSString *)[dic objectForKey:@"vlevel"]).intValue>((NSString *)[userArr[i] objectForKey:@"vlevel"]).intValue)
39             {
40                 j = i;
41                 [userArr insertObject:dic atIndex:j];
42                 break;
43             }
44         }
45     }
46 
47 
48 }

（1）直接调用系统的方法排序int

NSMutableArray*array = [[NSMutableArrayalloc]init];

[arrayaddObject:[NSNumbernumberWithInt:20]];

[arrayaddObject:[NSNumbernumberWithInt:1]];

[arrayaddObject:[NSNumbernumberWithInt:4]];

NSArray*sortedArray = [arraysortedArrayUsingSelector:@selector(compare:)];

for(inti =0; i < [sortedArraycount]; i++)

{

intx = [[sortedArrayobjectAtIndex:i]intValue];

NSLog(@"######%d\n", x);

}

（2）用descriptor方法

#import<Cocoa/Cocoa.h>

@interfaceNode: NSObject {

intx;

inty;

intv;

}

@property intx;

@property inty;

@property intv;

- (id)init:(int)tx y:(int)ty v:(int)tv;

@end

@implementationNode

@synthesizex;

@synthesizey;

@synthesizev;

- (id)init:(int)tx y:(int)ty v:(int)tv {

x= tx;

y= ty;

v= tv;

return self;

}

@end

intmain(intargc,char*argv[])

{

NSMutableArray *myMutableArray = [[NSMutableArrayalloc]init];

Node *n[2];

n[0] = [[Nodealloc]init:2y:1v:1];

n[1] = [[Nodealloc]init:4y:2v:2];

[myMutableArrayaddObject:n[0]];

[myMutableArrayaddObject:n[1]];

NSSortDescriptor* sortByA = [NSSortDescriptorsortDescriptorWithKey:@"x"ascending:NO];

[myMutableArraysortUsingDescriptors:[NSArrayarrayWithObject:sortByA]];

for(Node*tinmyMutableArray) {

NSLog(@"x === %d", t.x);

NSLog(@"y === %d", t.y);

NSLog(@"v === %d", t.v);

}

（3）自定义重写方法

Abstract:Constants returned by comparison functions, indicating whether a value is equal to, less than, or greater than another value.

Declaration:enumCFComparisonResult{

kCFCompareLessThan= -1,

kCFCompareEqualTo= 0,

kCFCompareGreaterThan= 1

};

#import<Cocoa/Cocoa.h>

@implementation NSNumber (MySort)

- (NSComparisonResult) myCompare:(NSString *)other {

//这里可以作适当的修正后再比较

int result = ([selfintValue]>>1) - ([other intValue]>>1);

//这里可以控制排序的顺序和逆序

return result < 0 ?NSOrderedDescending : result >0 ?NSOrderedAscending :NSOrderedSame;

}

@end

int main(int argc, char *argv[])

{

NSMutableArray *array = [[NSMutableArrayalloc]init];

[arrayaddObject:[NSNumbernumberWithInt:20]];

[arrayaddObject:[NSNumbernumberWithInt:1]];

[arrayaddObject:[NSNumbernumberWithInt:4]];

NSArray *sortedArray = [arraysortedArrayUsingSelector:@selector(myCompare:)];

for(int i = 0; i < [sortedArraycount]; i++)

{

int x = [[sortedArrayobjectAtIndex:i]intValue];

NSLog(@"######%d\n", x);

}

c语言实现的学生成绩管理系统是面向过程的,而OC实现的学生成绩管理系统则是面向对象的.

对该系统的重难点讲述如下:

1.排序.系统中的四个关键字分别是 stuID,姓名,年龄,成绩.我们可以选择这四种方式并选择升降序的方法进行排序.

系统中使用的是 NSmutableArray 存储数据.那么如何对对象是类成员的数组排序呢?

先看看NSMutableArray排序的几种方式.

1)使用@Seletor选择器调用方法排序.

[objc] view plain copy print ?

NSMutableArray *array = [[NSMutableArray alloc]init];
[array addObject:[NSNumber numberWithInt:10]];
[array addObject:[NSNumber numberWithInt:20]];
[array addObject:[NSNumber numberWithInt:0]];
[array addObject:[NSNumber numberWithInt:1]];
[array addObject:[NSNumber numberWithInt:3]];
NSLog(@"未排序的数组:%@",array);
NSArray *sortedArray = [array sortedArrayUsingSelector:@selector(compare:)];
NSLog(@"yi排序的数组:%@",sortedArray);
/*
2013-11-29 08:28:00.616 OC实现学生成绩管理系统[451:303] 未排序的数组:(
10,
20,
0,
1,
3
)
2013-11-29 08:28:00.621 OC实现学生成绩管理系统[451:303] yi排序的数组:(
0,
1,
3,
10,
20
)
*/

同时也适用于类对象.

[objc] view plain copy print ?

//直接实现静态方法，获取带有name和age的Person对象
+(Person *)personWithAge:(int) age withName:(NSString *)name{
Person *person = [[Person alloc] init];
person.age = age;
person.name = name;
return person;
}
//自定义排序方法
-(NSComparisonResult)comparePerson:(Person *)person{
//默认按年龄排序
NSComparisonResult result = [[NSNumber numberWithInt:person.age] compare:[NSNumber numberWithInt:self.age]];//注意:基本数据类型要进行数据转换
//如果年龄一样，就按照名字排序
if (result == NSOrderedSame) {
result = [self.name compare:person.name];
}
return result;
}

2.高级排序,使用排序描述器:使用descriptor方法对Array中成员是类对象的类型进行按@propery 列进行排序.

[objc] view plain copy print ?

-(void)SortStudentArray//
{
NSLog(@"按照学号排序请输入 (id)");
NSLog(@"按姓名排序请输入(name)");
NSLog(@"按照年龄排序请输入(age)");
NSLog(@"按照成绩排序(score)请输入:");
char charKey[10] ;
scanf("%s",charKey);
NSString *tempkey = [NSString stringWithUTF8String:charKey];
NSString *key = [tempkey lowercaseString];
BOOL ascending = NO;
NSLog(@"是否开启降序模式( 默认不开启 )?(yes or no):");
char ascendingStr[10] ;
scanf("%s",ascendingStr);
NSString *ascendingKey =[[NSString stringWithUTF8String:ascendingStr] lowercaseString];
if ([ascendingKey isEqualToString:@"yes"])
ascending = YES;
else
ascending = NO;
if ([key isEqualToString:@"id"]) {
NSSortDescriptor *sortByID = [NSSortDescriptor sortDescriptorWithKey:@"stuID" ascending:ascending];
// 建立NSSortDescriptor 对象,按照的属性列,是否是asc升序?

[objc] view plain copy print ?

[studentArray sortUsingDescriptors:[NSArray arrayWithObject:sortByID]];
//按照建立的descriptor进行排序.
}
else if([key isEqualToString:@"name"])
{
NSSortDescriptor *sortByName= [NSSortDescriptor sortDescriptorWithKey:@"name" ascending:ascending];
[studentArray sortUsingDescriptors:[NSArray arrayWithObject:sortByName]];
}
else if([ key isEqualToString:@"age"])
{
NSSortDescriptor *sortByAge = [NSSortDescriptor sortDescriptorWithKey:@"age" ascending:ascending];
[studentArray sortUsingDescriptors:[NSArray arrayWithObject:sortByAge]];
}
else if ([key isEqualToString:@"score"])
{
NSSortDescriptor *sortByScore = [NSSortDescriptor sortDescriptorWithKey:@"score" ascending:ascending];
[studentArray sortUsingDescriptors:[NSArray arrayWithObject:sortByScore]];
}
}

上述代码就是我在管理系统中实现的,结果将在系统中呈现.

3.自定义重写方法进行排序.使用Block进行排序.

[objc] view plain copy print ?

NSArray *array = [NSArray arrayWithObjects:@"1bc",@"4b6",@"123",@"789",@"3ef", nil nil];
NSArray *sortedArray = [array sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
//这里的代码可以参照上面compare:默认的排序方法，也可以把自定义的方法写在这里，给对象排序
NSComparisonResult result = [obj1 compare:obj2];
return result;
}];
NSLog(@"排序后:%@",sortedArray);

2013-11-29 08:42:56.723 OC实现学生成绩管理系统[483:303] 排序后:(

123,

1bc,

3ef,

4b6,

789

)

posted on 2014-08-01 10:59 三十一阅读(217) 评论(0) 编辑收藏举报

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