151 lines
2.9 KiB
C++
151 lines
2.9 KiB
C++
/* mbinary
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#########################################################################
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# File : map.cc
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# Author: mbinary
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# Mail: zhuheqin1@gmail.com
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# Blog: https://mbinary.xyz
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# Github: https://github.com/mbinary
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# Created Time: 2018-04-26 10:33
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# Description:
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#########################################################################
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*/
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#include<stdio.h>
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bool isZero(float a)
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{
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return a<0.00001&&-a<0.00001;
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}
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template<class,class> class map;
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//notice that if you declare a class template,declare the class first like this.
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template<class t1,class t2>
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class pair
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{
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friend class map<t1,t2>;
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pair<t1,t2> *next;
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public:
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t1 first;
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t2 second;
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};
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template<class t1,class t2>
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class map
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{
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int n;
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pair<t1,t2> head;
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int cur;
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pair<t1,t2> *last_visit;
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public:
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map();
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~map();
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bool has(t1);
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void erase(t1);
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t2& operator[](t1);
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pair<t1,t2> &locate(int index = -1);
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int size();
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};
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template<class t1,class t2>
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map<t1,t2>::map(){
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n=0;
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cur=-1;
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last_visit= &head;
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head.next=NULL;
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head.first = head.second = 0;
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}
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template<class t1,class t2>
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map<t1,t2>::~map()
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{
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pair<t1,t2> *p,*q=&head;
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while(q!=NULL){
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p=q->next;
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delete q;
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q=p;
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}
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}
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template<class t1,class t2>
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bool map<t1,t2>::has(t1 key)
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{
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pair<t1,t2> *p = head.next;
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for(int i = 0;i<n&&p->first<=key;++i){
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if(isZero(p->first-key)) return 1;
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p=p->next;
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}
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return 0;
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}
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template<class t1,class t2>
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pair<t1,t2>& map<t1,t2>::locate(int index)
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{
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if(index>=n||index<0){
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printf("the index is out of range\n");
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return head;
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}
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if(cur>index){
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last_visit = &head;
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cur = -1;
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}
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while(cur<index){
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last_visit = last_visit->next;
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++cur;
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}
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return *last_visit;
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}
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template<class t1,class t2>
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int map<t1,t2>::size()
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{
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return n;
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}
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template<class t1,class t2>
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t2& map<t1,t2>::operator[](t1 key)
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{
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pair<t1,t2> * p=&head;
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while(p->next!=NULL){
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if(isZero(p->next->first-key)) return p->next->second;
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else if(p->next->first>key){break;}
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p=p->next;
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}
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cur=-1;
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last_visit= &head;
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pair<t1,t2> *tmp = new pair<t1,t2>;
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tmp ->next = p->next;
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tmp->first = key;
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p->next = tmp;
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++n;
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return tmp->second;
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}
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template<class t1,class t2>
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void map<t1,t2>::erase(t1 key)
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{
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pair<t1,t2> *p = &head;
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while(p->next!=NULL){
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if(isZero(p->next->first-key)){
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pair<t1,t2> *q = p->next;
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p->next = p->next->next;
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delete q;
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--n;
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break;
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}
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p=p->next;
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}
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cur=-1;
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last_visit= &head;
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}
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int main()
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{
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map<double,float> b;
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for(int i = 0;i<40;++i){
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b[i] = i;
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if(i%3){
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b[i] = 1;
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}
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if(i%2){
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b.erase(i);
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}
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}
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for(int i = 0;i<b.size();++i){
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printf("item %d %g:%g\n",i,b.locate(i).first,b.locate(i).second);
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}
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return 0;
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}
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