第九周 标准模板库STL(二) - PKU[课程作业]程序设计与算法（三）C++面向对象程序设计

1:Set

#include<iostream>
#include<set>
#include<string>
using namespace std;
int main()
{
	int n;
	cin >> n;
	multiset<int> ms;
	set<int> s;
	multiset<int>::iterator pp;
	set<int>::iterator p;
	for( int i = 0; i < n; i++ )
	{
		string op; cin >> op;
		int a; cin >> a;
		switch(op[1])
		{
			case 'd':	// add
				ms.insert(a); s.insert(a);
				cout << ms.count(a) << endl;
				break;
			case 's':	// ask
				p = s.find(a);
				if( p != s.end() )
					cout << 1 << " ";
				else
					cout << 0 << " ";
				cout << ms.count(a) << endl;
				break;
			case 'e':	// del
				cout << ms.count(a) << endl;
				ms.erase(ms.lower_bound(a), ms.upper_bound(a));
				break;
			default:
				break;
		}
	}
	return 0;
}

2:热血格斗场

#include<iostream>
#include<set>
using namespace std;
#define MAX 1000000000 
struct member{
	int id;
	int ce;
};
struct rule{
	bool operator()( const member &a1, const member &a2 ){
		return (a1.ce < a2.ce);
	}
};
int main()
{
	int n;
	cin >> n;
	member a;
	set<member, rule> st;
	set<member, rule>::iterator p, p1, p2;
	a.id = 1;
	a.ce = MAX;
	st.insert(a);
	for( int i = 0; i < n; i++ )
	{
		scanf("%d%d", &a.id, &a.ce);
		st.insert(a);
		p1 = p2 = p = st.find(a);
		p2++;
		if( p1 != st.begin() ) p1--;
		if( p2 == st.end() ) p2--;
		if( p1 != p && p2 != p )
			if( p->ce - p1->ce <= p2->ce - p->ce )
				printf("%d %d\n", p->id, p1->id);
			else
				printf("%d %d\n", p->id, p2->id);
		else if( p1 == p && p2 != p )
				printf("%d %d\n", p->id, p2->id);
		else if( p1 != p && p2 == p )
			printf("%d %d\n", p->id, p1->id);
	}
	return 0;
}

3:冷血格斗场

#include<iostream>
#include<map>
using namespace std;
#define MAX 1000000000
struct member{
	int ce, id;
	// first, second
};
int id_LeftFindMin( multimap<int, int>::iterator p1 )
{
	member a;
	a.id = p1->second;
	a.ce = p1->first;
	while( (--p1)->first == a.ce )
		if( p1->second < a.id )
			a.id = p1->second;
	return a.id;
}
int id_RightFindMin( multimap<int, int>::iterator p2 )
{
	member a;
	a.id = p2->second;
	a.ce = p2->first;
	while( (++p2)->first == a.ce )
		if( p2->second < a.id )
			a.id = p2->second;
	return a.id;
}
int main()
{
	int n;
	cin >> n;
	multimap<int, int> mp;	// int first -- int ce, int second -- int id
	member a;
	a.id = 1;
	a.ce = MAX;
	mp.insert(make_pair(a.ce, a.id));
	multimap<int, int>::iterator p, p1, p2;
	for( int i = 0; i < n; i++ )
	{
		scanf("%d%d", &a.id, &a.ce);
		p = p1 = p2 = mp.insert(make_pair(a.ce, a.id));
		if( p1 != mp.begin() ) p1--;
		if( ++p2 == mp.end() ) p2--;
		if( p1 != p && p2 != p ){
			if( p->first - p1->first < p2->first - p->first )
				a.id = id_LeftFindMin(p1);
			else if( p->first - p1->first > p2->first - p->first )
				a.id = id_RightFindMin(p2);
			else{	// p->first - p1->first == p2->first - p->first
				p1->second = id_LeftFindMin(p1);
				p2->second = id_RightFindMin(p2);
				a.id = (p1->second < p2->second) ? p1->second : p2->second;
			}
		}
		else if( p1 == p && p2 != p )
			a.id = id_RightFindMin(p2);
		else if( p1 != p && p2 == p )
			a.id = id_LeftFindMin(p1);
		printf("%d %d\n", p->second, a.id);
	}
	return 0;
}

4:编程填空：数据库内的学生信息

#include <iostream>
#include <string>
#include <map>
#include <iterator>
#include <algorithm>
using namespace std;

template< class Key, class Val, class Pred = greater<Key> >
class MyMultimap: public multimap<Key,Val,Pred>
{
	public:
		void Set(Key key, Val value)
		{
			typedef typename multimap<Key, Val, Pred>::iterator myIt;
//			pair<myIt,myIt> bounds = this->equal_range(key);
//			for( myIt it = bounds.first; it != bounds.second; it++ )
//				it->second = value;
//    或者下面这种写法
			for( myIt it = this->find(key); it->first == key; it++ )
				it->second = value;
		}
};
template<class T1, class T2>
ostream & operator<<( ostream & os, pair<T1,T2>p )
{
	os << "(" << p.first << "," << p.second << ")";
	return os;
}

struct Student 
{
	string name;
	int score;
};
template <class T>
void Print(T first,T last) {
	for(;first!= last; ++ first)
		cout << * first << ",";
	cout << endl;
}
int main()
{
	
	Student s[] = { {"Tom",80},{"Jack",70},
					{"Jone",90},{"Tom",70},{"Alice",100} };
	
	MyMultimap<string,int> mp;
	for(int i = 0; i<5; ++ i)
		mp.insert(make_pair(s[i].name,s[i].score));
	Print(mp.begin(),mp.end()); //按姓名从大到小输出

	mp.Set("Tom",78); //把所有名为"Tom"的学生的成绩都设置为78
	Print(mp.begin(),mp.end());
	
	
	
	MyMultimap<int,string,less<int> > mp2;
	for(int i = 0; i<5; ++ i) 
		mp2.insert(make_pair(s[i].score,s[i].name));
	
	Print(mp2.begin(),mp2.end()); //按成绩从小到大输出
	mp2.Set(70,"Error");          //把所有成绩为70的学生，名字都改为"Error"
	Print(mp2.begin(),mp2.end());
	cout << "******" << endl;
	
	mp.clear();
	
	string name;
	string cmd;
	int score;		
	while(cin >> cmd ) {
		if( cmd == "A") {
			cin >> name >> score;
			if(mp.find(name) != mp.end() ) {
				cout << "erroe" << endl;
			}
			mp.insert(make_pair(name,score));
		}
		else if(cmd == "Q") {
			cin >> name;
			MyMultimap<string,int>::iterator p = mp.find(name);
			if( p!= mp.end()) {
				cout << p->second << endl;
			}
			else {
				cout << "Not Found" << endl; 
			}
		}
	}
	return 0;
}