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更新时间：2022-09-16 17:50:13
队列和栈是最常用的数据结构，跟栈不同的是栈是先进后出，队列是先进先出，生活中简单的队列的例子比如说排队买票，排队等公交，具体的原理可以参考网上，基本上大同小异，本文简单的实现一下队列的入列，出列和删除的操作,跟栈一样，队列是通过Node关联操作，具体实现如下:
Node定义:
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@interface Node : NSObject
@property (strong,nonatomic) NSString *value;
@property (strong,nonatomic) Node *next;
@end |
Queue.h文件:
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@interface Queue : NSObject
//最先入列的元素@property (strong,nonatomic) Node *first;
//最后入列的元素@property (strong,nonatomic) Node *last;
@property (assign,nonatomic) NSInteger count;
-(BOOL)isEmpty;
-(NSInteger)size;
-(void)enqueue:(NSString *)value;
-(NSString *)dequeue;
-(void)remove:(NSString *)value;
@end |
Queue.m代码:
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@implementation Queue
-(BOOL)isEmpty{
return self.count==0;
}-(NSInteger)size{
return self.count;
}-(void)enqueue:(NSString *)value{
Node *oldLast=self.last;
self.last=[[Node alloc]init];
self.last.value=value;
self.last.next=NULL;
oldLast.next=self.last;
if ([self isEmpty]) {
self.first=self.last;
}else{
oldLast.next=self.last;
}
self.count=self.count+1;
}-(NSString *)dequeue{
if ([self isEmpty]) {
return [NSString stringWithFormat:@"-1"];
}
NSString *result=self.first.value;
self.first=self.first.next;
self.count=self.count-1;
return result;
}-(void)remove:(NSString *)value{
//判断是不是头部节点
if ([self.first.value isEqualToString:value]) {
self.first=self.first.next;
self.count=self.count-1;
}else{
Node *node=self.first;
while (node!=NULL) {
if ([node.next.value isEqualToString:value]) {
node.next=node.next.next;
self.count=self.count-1;
break;
}
node=node.next;
}
}
}@end |
调用如下:
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Queue *queue=[[Queue alloc]init];[queue enqueue:@"iOS技术交流群:228407086"];
[queue enqueue:@"FlyElephant"];
[queue enqueue:@"博客园"];
[queue enqueue:@"keso"];
[queue remove:@"keso"];
NSLog(@"出队列:%@",queue.dequeue);
NSLog(@"出队列:%@",queue.dequeue);
NSLog(@"出队列:%@",queue.dequeue);
NSLog(@"出队列:%@",queue.dequeue);
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输出如下:
本文转自Fly_Elephant博客园博客，原文链接：http://www.cnblogs.com/xiaofeixiang/p/4562146.html，如需转载请自行联系原作者