【每日刷题】Day100
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🌼文章目录🌼
1. 【模板】堆_牛客题霸_牛客网 (nowcoder.com)
2. 【模板】链表_牛客题霸_牛客网 (nowcoder.com)
3. 【模板】队列_牛客题霸_牛客网 (nowcoder.com)
1. 【模板】堆_牛客题霸_牛客网 (nowcoder.com)
//C++堆(大堆)的实现。
#include <iostream>
#include <vector>
using namespace std;
class Heap
{
public:
Heap()
:_size(0)
{}
void Swap(int& x,int& y)
{
int tmp = x;
x = y;
y = tmp;
}
//向下调整void AdjustDown(int parents)
{
int child = parents*2+1;
while(child<_size)
{
if(child+1<_size&&_arr[child+1]>_arr[child])
child++;
if(_arr[child]>_arr[parents])
Swap(_arr[child],_arr[parents]);
else
break;
parents = child;
child = parents*2+1;
}
}
//向上调整
void Adjustup(int child)
{
int parents = (child-1)/2;
while(child>0)
{
if(_arr[child]>_arr[parents])
Swap(_arr[child],_arr[parents]);
else
break;
child = parents;
parents = (child-1)/2;
}
}
//入堆
void push(int val)
{
_arr.push_back(val);
Adjustup(_size);
_size++;
}
//删除堆顶元素
void pop()
{
if(_size==0)
cout<<"empty"<<endl;
else
{
cout<<_arr[0]<<endl;
Swap(_arr[0],_arr[_size-1]);
_arr.pop_back();
_size--;
AdjustDown(0);
}
}
//获取堆顶元素
void top()
{
if(_size==0)
cout<<"empty"<<endl;
else
cout<<_arr[0]<<endl;
}
private:
vector<int> _arr;
size_t _size;
};
int main()
{
Heap h;
int n = 0;
cin>>n;
while(n--)
{
int data = 0;
string s;
cin>>s;
if(s=="push")
{
cin>>data;
h.push(data);
}
if(s=="top")
h.top();
if(s=="pop")
h.pop();
}
return 0;
}
2. 【模板】链表_牛客题霸_牛客网 (nowcoder.com)
//C++链表模拟实现。
#include <iostream>
#include <list>
using namespace std;
class List
{
class list_node
{
public:
list_node(int y = -2147483648)
:next(nullptr)
,val(y)
{}
int val;
list_node* next;
};
public:
List()
:head(new list_node)
,_size(0)
{}
//打印链表
void printf()
{
if(_size)
{
list_node* pmove = head->next;
while(pmove)
{
cout<<pmove->val<<' ';
pmove = pmove->next;
}
}
else
cout<<"NULL";
}
//在值为x的节点前插入值为y的节点
void Insert(int x,int y)
{
list_node* pnext = head->next;
list_node* prev = head;
while(pnext&&pnext->val!=x)
{
prev = prev->next;
pnext = pnext->next;
}
list_node* newnode = new list_node(y);
prev->next = newnode;
newnode->next = pnext;
_size++;
}
//删除值为x的节点
void Delete(int x)
{
list_node* pmove = head->next;
list_node* prev = head;
while(pmove&&pmove->val!=x)
{
prev = prev->next;
pmove = pmove->next;
}
if(pmove)
{
prev->next = pmove->next;
_size--;
delete pmove;
}
}
private:
list_node* head;
size_t _size;
};
int main()
{
List l;
int n = 0;
cin>>n;
while(n--)
{
int x,y;
string s;
cin>>s;
if(s=="insert")
{
cin>>x>>y;
l.Insert(x, y);
}
if(s=="delete")
{
cin>>x;
l.Delete(x);
}
}
l.printf();
return 0;
}
3. 【模板】队列_牛客题霸_牛客网 (nowcoder.com)
//C++队列的实现。
#include <iostream>
#include <list>
#include <string>
using namespace std;
class Queue
{
class queue_node
{
public:
queue_node(int _val = -2147483648)
:next(nullptr)
,val(_val)
{}
int val;
queue_node* next;
};
public:
Queue()
:head(new queue_node)
,pmove(head)
,_size(0)
{}
//获取队头元素
void front()
{
if(_size)
cout<<head->next->val<<endl;
else
cout<<"error"<<endl;
}
//队尾插入元素
void Push(int data)
{
queue_node* newnode = new queue_node(data);
pmove->next = newnode;
pmove = pmove->next;
_size++;
}
//队头删除元素
void pop()
{
if(_size)
{
queue_node* pnext = head->next->next;
queue_node* pcur = head->next;
cout<<pcur->val<<endl;
if(pcur==pmove)
pmove = head;
head->next = pnext;
delete pcur;
_size--;
}
else
cout<<"error"<<endl;
}
private:
queue_node* head;
queue_node* pmove;
size_t _size;
};
int main()
{
Queue q;
int n;
cin>>n;
while(n--)
{
int data;
string s;
cin>>s;
if(s=="push")
{
cin>>data;
q.Push(data);
}
if(s=="pop")
q.pop();
if(s=="front")
q.front();
}
return 0;
}