C++程序设计原理与实践 第五章部分答案

 1 #include "../../st.h"
 2 
 3 int main()
 4 {
 5     vector<double> nums;
 6     double t;
 7     int n;
 8     cout<<"input how many nums: ";
 9     cin>>n;
10     cin>>t;
11     nums.push_back(t);
12     int i=0;
13     while(cin>>t)
14     {
15         if(i<n-1&&nums[i]!=t)
16         {
17             nums.push_back(t);
18             i++;
19         }
20     }
21     double sum=0;
22     for(i=0;i<nums.size();i++)
23     {
24         cout<<nums[i]<<"  ";
25         sum+=nums[i];
26     }
27     cout<<endl<<"the count is "<<sum<<endl;
28     keep_window_open();
29     return 0;
30 }

 1 #include "../../st.h"
 2 
 3 //maybe can be better
 4 //利用  narrow_cast<>
 5 //这个版本没有
 6 
 7 int main()
 8 try
 9 {
10     int x1=0,x2=1,x=x1+x2;
11     bool b=1;
12     cout<<x1<<endl<<x2<<endl<<x<<endl;
13     while(x>=0)
14     {
15         cout<<x<<endl;
16         x=x1+x2;
17         
18         x1=x2;
19         x2=x;
20     }
21     keep_window_open();
22     return 0;
23 }
24 
25 catch(runtime_error)
26 {
27     cout<<"it is over."<<endl;
28     keep_window_open();
29     return 1;
30 }

 1 #include "../../st.h"
 2 
 3 //利用两个数组储存
 4 
 5 int main()
 6 {
 7     int a=1224;         //设定初始数
 8     int b;                //我们猜测的数
 9     int n,m;
10     int i,j,t;
11     int aa[4];     //存原始数的每个数字
12     int bb[4];       //我们猜测的数的每个数字
13     for(i=3;i>=0;i--)
14     {
15         aa[i]=a%10;
16         a/=10;
17     }
18     while(1)
19     {
20         cin>>b;
21         n=m=0;
22         for(i=3;i>=0;i--)
23         {
24             bb[i]=b%10;
25             b/=10;
26         }
27 
28         for(i=0;i<4;i++)
29             if(aa[i]==bb[i])
30                 n++;
31         if(n==4)
32         {
33             cout<<"4 gong"<<endl;
34             break;
35         }
36         for(i=0;i<4;i++)
37             for(j=0;j<3-i;j++)
38                 if(bb[j]>bb[j+1])
39                 {
40                     t=bb[j];
41                     bb[j]=bb[j+1];
42                     bb[j+1]=t;
43                 }
44         for(i=0;i<4;i++)
45         {
46             for(j=0;j<4;j++)
47                 if(aa[i]==bb[j]){
48                     m++;
49                     break;
50                 }
51         }
52         cout<<m<<endl;
53         m-=n;
54         cout<<n<<" gong,"<<m<<" mu"<<endl;
55     }
56     return 0;
57 }

 1 //为第六章习题8  但4个数字改为4个字母
 2 #include "../../st.h"
 3 
 4 int main()
 5 {
 6     char a[4]={‘a‘,‘b‘,‘b‘,‘c‘};
 7     char b;
 8     int n,m;
 9     int i,j,t;
10     int aa[4],bb[4];
11     for(i=0;i<4;i++)
12         {
13             aa[i]=a[i];
14         }
15     while(1)
16     {
17         
18         n=m=0;
19         for(i=0;i<4;i++)
20         {
21             cin>>b;
22             bb[i]=b;
23         }
24 
25 
26         for(i=0;i<4;i++)
27             if(aa[i]==bb[i])
28                 n++;
29         if(n==4)
30         {
31             cout<<"4 gong"<<endl;
32             break;
33         }
34         for(i=0;i<4;i++)
35             for(j=0;j<3-i;j++)
36                 if(bb[j]>bb[j+1])
37                 {
38                     t=bb[j];
39                     bb[j]=bb[j+1];
40                     bb[j+1]=t;
41                 }
42         for(i=0;i<4;i++)
43         {
44             for(j=0;j<4;j++)
45                 if(aa[i]==bb[j]){
46                     m++;
47                     break;
48                 }
49         }
50         m-=n;
51         cout<<n<<" gong,"<<m<<" mu"<<endl;
52     }
53 
54     while(1);
55     return 0;
56 }