C + + Brush question two

(i) there is a fractional sequence: 2/1 3/2 5/3 8/5 13/8 21/13 ... The sum of the first n items of this sequence is calculated, and two decimal places are reserved. #include <iostream> #include <iomanip>using namespace Std;int main () {    int i,n;    Double m=2.0,n=1.0,s,sum=0;    cin>>n;    for (i=0;i<n;i++)    {        sum=m/n+sum;        S=m+n;        n=m;        m=s;    }    Cout<<setiosflags (ios::fixed) <<setprecision (2) <<sum<<endl;    return 0;}

(ii) Write a function that connects two strings 123     abc123abc#include <iostream> #include <string>using namespace Std;int main () {    string A, B;    int i;    cin>>a>>b;    cout<<a;    for (i=0;a[i]!= ' n '; i++);    cout<<b;    return 0;}

(c) Write a function, enter a four-digit number, which requires the output of these four numeric characters, but each of the two digits between the spaces. If you enter 1990, you should output "1 9 9 0". #include <iostream>using namespace std;void output (int num,int n); int main () {    int num,n=4;    cin>>num;    Output (num,n);    return 0;} void output (int num,int n) {    int a[n],i=1;    while (num>0)    {        a[i]=num%10;        NUM=NUM/10;        i++;    }    for (i=n; i>1; i--)        cout<<a[i]<< "";    Cout<<a[1]<<endl;}

(d) Write a function, copy the vowel letters from two strings to another string, and then output. #include <iostream> #include <string>using namespace Std;int main () {    string a B;    int i;    cin>>a>>b;    for (i=0; a[i]!= '; i++)    {        if (a[i]== ' A ' | | a[i]== ' E ' | | a[i]== ' I ' | | a[i]== ' O ' | | a[i]== ' u ')            cout<<a[i];    }    for (i=0; b[i]!= '; i++)    {        if (b[i]== ' A ' | | b[i]== ' E ' | | b[i]== ' I ' | | b[i]== ' O ' | | b[i]== ' u ')            cout<<b[i];    }    return 0;}

(v) Set Circle radius r, cylindrical high h for circular long C1, Circle area sa, sphere surface area sb, sphere Volume VA, cylindrical volume VB. Input data with scanf, output calculation results, the output requires text description, take the decimal point after two digits. Please compile the program. Pi=3.14#include <iostream> #include <iomanip>using namespace Std;int main () {    float r,h;    Double Pi=3.14,c1,sa,sb,va,vb;    cin>>r>>h;    C1=pi*2*r;    Sa=pi*r*r;    Sb=4*pi*r*r;    VA=PI*R*R*R*4/3;    vb=pi*r*r*h-0.005;    Cout<<setiosflags (ios::fixed) <<setprecision (2);    cout<< "c1=" <<C1<<endl;    cout<< "Sa=" <<Sa<<endl;    cout<< "sb=" <<Sb<<endl;    cout<< "Va=" <<Va<<endl;    cout<< "vb=" <<Vb<<endl;    return 0;}

(vi) Write a function that causes the input string to be stored in reverse order, and enter the output back-order string in the main function. #include <iostream> #include <string>using namespace Std;int main () {    string A;    cin>>a;    int i,n;    for (i=0;a[i]!= ' n '; i++)    {        n=i;    }    for (i=n;i>=0;i--)    {        cout<<a[i];    }    return 0;}

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C + + Brush question two