1 #include <iostream>
2 using namespace std;
3
4 int main()
5 {
6 int a=1,b=100;
7 int f=1;
8 char c=0;
9
10 while(f<=7 && (b-a)>=1)
11 {
12 cout<<"你的数小等于"<<(a+b)/2<<"吗？(y/n)";
13 cin>>c;
14 if(c==‘n‘)
15 a=(a+b)/2+1;
16 else
17 b=(a+b)/2;
18 f++;
19 }
20 cout<<(a+b)/2<<endl;
21 while (true);
22 }
第4题
1 #include "../../st.h"
2
3 int main()
4 {
5 int sum=0;
6 int i=1;
7 while(sum<1000)
8 {
9 int s=1;
10 for(int n=1;n<i;n++)
11 s*=2;
12 sum+=s;
13 i++;
14 }
15
16 cout<<"it is "<<i-1<<endl;
17
18 while(1);
19 return 0;
20 }
第8题
1 #include "../../st.h"
2 //要得到自然数n以内的全部素数，必须把不大于的所有素数的倍数剔除，剩下的就是素数。
3 const int MAX=101;
4
5 int main()
6 {
7 int all[MAX];
8 int N,i,j,s;
9 // memset(all,1,sizeof(all));
10 for(i=0;i<MAX;i++) //初始化
11 all[i]=1;
12
13 for(i=2;i<MAX;i++) //倍数关系
14 if(all[i])
15 for(j=i+i;j<=MAX;j+=i)
16 all[j]=0;
17 while(cin>>N)
18 {
19 for(i=2;i<=N;i++)
20 if(all[i])
21 cout<<i<<" ";
22 cout<<endl;
23 }
24 return 0;
25 }
第13题
1 #include "../../st.h"
2 //学到后面这些都是小case= =
3 int main()
4 {
5 vector<int> all;
6 vector<int> s;
7 vector<int> n;
8 int t;
9 while(cin>>t)
10 all.push_back(t);
11 sort(all.begin(),all.end());
12 t=all[0];
13 int k=0;
14 for(int i=0;i<all.size();i++){
15 if(t==all[i])
16 k++;
17 else
18 {
19 s.push_back(t);
20 n.push_back(k);
21 t=all[i];
22 k=1;
23 }
24 }
25 s.push_back(t);
26 n.push_back(k);
27 int max=0;
28 for(t=0;t<n.size();t++)
29 if(max<n[t])
30 max=n[t];
31 for(t=0;t<n.size();t++)
32 if(n[t]==max)
33 cout<<"the most number is "<<s[t]<<endl;
34
35 while(1);
36 return 0;
37 }
第16题
1 #include "../../st.h"
2
3 int main()
4 {
5 vector<string> names;
6 vector<double> scores;
7 string t;
8 double n;
9 int i;
10 while(1)
11 {
12 cout<<"input name: ";
13 cin>>t;
14
15 if(t=="no"){
16 cin>>t;
17 break;
18 }
19 for(i=0;i<names.size();i++)
20 if(names[i]==t){
21 cout<<"this is error";
22 exit(1);
23 }
24 names.push_back(t);
25 cout<<"input scores:";
26 cin>>n;
27 scores.push_back(n);
28
29 }
30 for(i=0;i<names.size();i++)
31 cout<<names[i]<<"-"<<scores[i]<<endl;
32 cout<<endl;
33
34 cout<<"input the name:";
35 cin>>t;
36 int f=0;
37 for(i=0;i<names.size();i++)
38 if(t==names[i]){
39 f=1;
40 break;
41 }
42 if(f==1)
43 cout<<t<<"‘s score is "<<scores[i]<<endl;
44 else
45 cout<<"not found."<<endl;
46
47 cout<<"input the score:";
48 cin>>n;
49 f=0;
50 for(i=0;i<scores.size();i++)
51 if(n==scores[i]){
52 f=1;
53 cout<<names[i]<<endl;
54 }
55 if(f==0)
56 cout<<"score not found."<<endl;
57
58 while(1);
59 return 0;
60 }
第19题
1 //第六章习题4 一个vector取代两个vector
2 #include "../../st.h"
3
4 class Name_value{
5 public:
6 string name;
7 double val;
8
9 Name_value(string s,double d);
10 };
11
12 Name_value::Name_value(string s,double d)
13 {
14 name=s;
15 val=d;
16 }
17
18 int main()
19 {
20 vector<Name_value> nv;
21 string s;
22 double d;
23 int i;
24 while(1)
25 {
26 cout<<"input name: ";
27 cin>>s;
28
29 if(s=="no")
30 {
31 cin>>s;
32 break;
33 }
34 for(i=0;i<nv.size();i++)
35 if(nv[i].name==s)
36 {
37 cout<<"this is error";
38 exit(1);
39 }
40 cout<<"input scores:";
41 cin>>d;
42 Name_value nv1(s,d);
43 nv.push_back(nv1);
44 }
45 for(i=0;i<nv.size();i++)
46 cout<<nv[i].name<<"-"<<nv[i].val<<endl;
47 cout<<endl;
48
49 cout<<"input the name:";
50 cin>>s;
51 int f=0;
52 for(i=0;i<nv.size();i++)
53 if(s==nv[i].name){
54 f=1;
55 break;
56 }
57 if(f==1)
58 cout<<s<<"‘s score is "<<nv[i].val<<endl;
59 else
60 cout<<"not found."<<endl;
61
62 cout<<"input the score:";
63 cin>>d;
64 f=0;
65 for(i=0;i<nv.size();i++)
66 if(d==nv[i].val){
67 f=1;
68 cout<<nv[i].name<<endl;
69 }
70 if(f==0)
71 cout<<"score not found."<<endl;
72
73 while(1);
74
75 return 0;
76 }
第19题改
简单练习
总的来说 这一章是很容易的 理解了就OK
时间： 2024-12-24 08:59:32