1 #include <iostream>
2 #include <vector>
3 #include <string>
4 #include <list>
5 #include<fstream>
6 #include<algorithm>
7 #include<stdexcept>
8 using namespace std;
9
10 struct Item
11 {
12 string name;
13 int iid;
14 double value;
15 Item(string s,int i,double d):name(s),iid(i),value(d){}
16 Item(){}
17 Item(string s):name(s){}
18 };
19
20 ostream& operator<<(ostream&os,Item&i)
21 {
22 os<<i.name<<‘\t‘<<‘\t‘<<i.iid<<‘\t‘<<i.value;
23 return os;
24 }
25
26 istream& operator>>(istream&is,Item&i)
27 {
28 is>>i.name>>i.iid>>i.value;
29 return is;
30 }
31
32 struct sort_name
33 {
34 bool operator()(const Item&i1,const Item&i2) const
35 {
36 if(i1.name<=i2.name)
37 return true;
38 else
39 {
40 return false;
41 }
42 }
43 };
44
45 struct find_name
46 {
47 string s2;
48 find_name(string s1):s2(s1){}
49 bool operator()(const Item&i) const
50 {
51 if(i.name==s2)
52 return true;
53 else
54 {
55 return false;
56 }
57 }
58 };
59
60 void find_earse(vector<Item>&vi,const string &n)
61 {
62 vector<Item>::iterator p=vi.begin();
63 while(p!=vi.end())
64 {
65 if(p->name==n)
66 break;
67 p++;
68 }
69 vi.erase(p);
70 }
71
72 int main()
73 {
74 vector<Item> vi;
75 Item item;
76 int i;
77 string a;
78 cin>>a;
79
80 ifstream ifs(a.c_str());
81 if(!ifs)
82 cerr<<"can not open input file1";
83 for(i=0;i<10;i++)
84 {
85 ifs>>item;
86 vi.push_back(item);
87 }
88
89 sort(vi.begin(),vi.end(),sort_name());
90
91 item=Item("hourse shoe",99,12.34);
92 vi.insert(vi.begin(),item);
93 item=Item("Canon s400",9899,499.14);
94 vi.insert(vi.begin(),item);
95
96 find_earse(vi,"kj");
97 find_earse(vi,"oj");
98
99 for(i=0;i<10;i++)
100 {
101 cout<<vi[i]<<endl;
102 }
103
104 vector<Item>::iterator p=find_if(vi.begin(),vi.end(),find_name("dio"));
105 cout<<*p<<endl;
106 while(1);
107 return 0;
108
109 }
简单练习
1 int count1(In first,In last,const T&val)
2 {
3 int i=0;
4 while(first!=last){
5 if(*first==val)
6 i++;
7 first++;
8 }
9 return i;
10 }
11
12 template<class In,class Pred>
13 int count_if1(In first,In last,Pred pred)
14 {
15 int i=0;
16 while(first!=last){
17 if(pred(*first))
18 i++;
19 first++;
20 }
21 return i;
22 }
习题3 4
1 #include <iostream>
2 #include <vector>
3 #include <string>
4 #include <list>
5 #include<fstream>
6 #include <set>
7 //#include<algorithm>
8 #include<stdexcept>
9 #include <map>
10 using namespace std;
11
12 struct Fruit
13 {
14 string name;
15 int count;
16 Fruit(string s,int i):name(s),count(i){}
17 };
18
19 struct Fruit_order
20 {
21 bool operator()(const Fruit*a,const Fruit*b)const
22 {
23 return a->name<b->name;
24 }
25 };
26
27 ostream& operator<<(ostream&os,const Fruit* f)
28 {
29 os<<f->name<<" "<<f->count;
30 return os;
31 }
32
33 int main()
34 {
35
36 set<Fruit*,Fruit_order> in;
37 in.insert(new Fruit("fa",33));
38 in.insert(new Fruit("as",83));
39 typedef set<Fruit*>::iterator s1;
40 for(s1 p=in.begin();p!=in.end();p++)
41 cout<<*p<<endl;
42 while(1);
43 return 0;
44
45 }
习题6
1 #include <iostream>
2 #include <vector>
3 #include <string>
4 #include <list>
5 #include<fstream>
6 #include <set>
7 #include<algorithm>
8 #include<stdexcept>
9 #include <map>
10 using namespace std;
11
12 struct Purchase
13 {
14 string name;
15 double unit_price;
16 int count;
17
18 };
19
20 struct Order{
21 string name;
22 string add;
23 double data;
24 vector<Purchase> vp;
25 bool operator < (const Order&o) const
26 {
27 //return cig_quantity>b1.cig_quantity;
28 //按照名字的大小顺序进行排序
29 return name>o.name;
30 }
31 };
32
33 istream& operator>>(istream&is,Purchase&p)
34 {
35 is>>p.name>>p.unit_price>>p.count;
36 return is;
37 }
38
39 istream& operator>>(istream&is,Order&o)
40 {
41 is>>o.name>>o.add>>o.data;
42 char c;
43 is>>c;
44 Purchase p;
45 while(c==‘(‘)
46 {
47 is>>p;
48 o.vp.push_back(p);
49 is>>c;
50 is>>c;
51 }
52 if(c!=‘(‘)
53 is.putback(c);
54 return is;
55
56 }
57
58 ostream& operator<<(ostream&os,Purchase&p)
59 {
60 os<<p.name<<‘ ‘<<p.unit_price<<‘ ‘<<p.count;
61 return os;
62 }
63
64 ostream& operator<<(ostream&os,Order&o)
65 {
66 os<<o.name<<‘ ‘<<o.add<<‘ ‘<<o.data<<‘ ‘;
67 for(int i=0;i<o.vp.size();i++)
68 os<<‘(‘<<o.vp[i].name<<‘ ‘<<o.vp[i].unit_price<<‘ ‘<<o.vp[i].count<<‘)‘;
69 return os;
70
71 }
72
73 struct sort_name
74 {
75 bool operator()(const Order&o1,const Order&o2) const
76 {
77 if(o1.name<=o2.name)
78 return true;
79 else
80 {
81 return false;
82 }
83 }
84 };
85
86 int main()
87 {
88 vector<Order> vo;
89 list<Order>lo;
90 string a;
91 int i=0;
92 //Order o; //注意不要放在这里
93
94 cin>>a;
95 ifstream ifs(a.c_str());
96 if(!ifs)
97 cerr<<"can not open input file1";
98 for(i=0;i<10;i++)
99 {
100 Order o; //应该放在这
101 ifs>>o;
102 vo.push_back(o);
103 }
104 ifs.close();
105 sort(vo.begin(),vo.end(),sort_name());
106
107 cin>>a;
108 fstream ofs(a.c_str());
109 if(!ofs)
110 cerr<<"can not open input file1";
111 for(i=0;i<vo.size();i++)
112 ofs<<vo[i]<<endl;
113
114
115 cin>>a;
116 ifstream ifs1(a.c_str());
117 if(!ifs1)
118 cerr<<"can not open input file1";
119 for(i=0;i<10;i++)
120 {
121 Order o; //应该放在这
122 ifs1>>o;
123 lo.push_back(o);
124 }
125 ifs1.close();
126 lo.sort();
127
128
129 cin>>a;
130 fstream ofs1(a.c_str());
131 if(!ofs1)
132 cerr<<"can not open input file1";
133 for(list<Order>::iterator p=lo.begin();p!=lo.end();p++)
134 ofs1<<*p<<endl;
135
136
137 vector<Order> vo1(vo.size()+lo.size());
138 merge(vo.begin(),vo.end(),lo.begin(),lo.end(),vo1.begin());
139 cin>>a;
140 fstream f(a.c_str());
141 if(!f)
142 cerr<<"can not open input file1";
143
144 while(1);
145 return 0;
146
147 }
习题9
习题8 先找出最大频率 然后再遍历输出
习题10 accumulate()
习题14 map储存 s[][0]==‘s‘ size()
时间： 2024-10-12 04:37:12