第七周作业

1.调试分析课本每一个例题，有可能的话更改成2-3个方法的新程序

例1

#include<iostream>using namespace std;void display(){cout<<"This is an example."<<endl;}int main(){display();return 0;}

例2

#include<iostream>using namespace std;double min(double x,double y){return x<y?x:y;}int main(){cout<<min(6.0,5.0)<<endl;return 0;}

例3

#include<iostream>using namespace std;double circleArea(double);int main(){double area=circleArea(5.0);cout<<"area="<<area<<endl;return 0;}double circleArea(double r){double pi=3.14;double area=pi*r*r;return area;}

例4

#include<iostream>using namespace std;int sum(int x,int y){int temp;temp=x+y;return temp;}int main(){int a,b,c;a=10;b=5;c=sum(a,b);cout<<a<<"+"<<b<<"="<<c<<endl;return 0;}

例5

#include<iostream>using namespace std;int ncomp(int i,int j){if(i>j)return 1;if(i==j)return 0;return -1;}int main(){int k=2;int n=ncomp(k,++k);cout<<n;return 0;}

这个c++系统是从右到左的处理顺序

例6

#include<iostream>using namespace std;int max(int u,int v){int w;w=u>v?u:v;return w;}int main(){int a,b,c;cout<<"Please input two numbers:";cin>>a>>b;c=max(a,b);cout<<"a="<<a<<" b="<<b<<endl;cout<<"Max is 5"<<c<<endl;return 0;}

例7

#include<iostream>using namespace std;int sqr(int x){x=x*x;return x;}int main(){int t=10;int s=sqr(t);cout<<"t="<<t<<'\t'<<"sqt("<<t<<")="<<s<<endl;return 0;}

例8

#include<iostream>using namespace std;void swap(int u,int v);int main(){ int a=3; int b=4; cout<<"a="<<a<<"\tb="<<b<<endl; swap(a,b); cout<<"a="<<a<<"\tb="<<b<<endl; return 0;}void swap(int u,int v){ int temp; temp=u; u=v; v=temp;}

例9

#include<iostream>using namespace std;void swap(int&u,int &);int main(){    int a=3;int b=4;cout<<"a ="<<a<<"\tb ="<<b<<endl;swap(a,b);cout<<"a ="<<a<<"\tb ="<<b<<endl;return 0;}void swap(int &u,int &v){    int temp = v;v=u;u=temp;}

例10

#include<iostream>using namespace std;void display(int x,float y){   cout<<x<<" "<<y;   return;}int main(){   float a;   int b;   cin>>b>>a;   display(b,a);   return 0;}

例11

#include<iostream>#include<cmath>using namespace std;void GetRoots(/*in*/double,/*in*/double,/*in*/double,  /*out*/double&,/*out*/double&);int main(){    double a,b,c;double root1,root2;    cout<<"输入方程的三个系数a,b,c:"<<endl;cin>>a>>b>>c;GetRoots(a,b,c,root1,root2);cout<<"root1= "<<root1<<"root2 ="<<root2<<endl;return 0;}void GetRoots(/*in*/double a,/*in*/double b,/*in*/double c,  /*out*/double&root1,/*out*/double&root2){    double temp;temp=b*b-4.0*a*c;    root1=(-b+sqrt(temp))/(2.0/a);root2=(-b-sqrt(temp))/(2.0/a);}

例12

#include<iostream>using namespace std;void swap(/*inout*/int&u,/*inout*/int &);int main(){    int a=3;int b=4;cout<<"a ="<<a<<"\tb ="<<b<<endl;swap(a,b);cout<<"a ="<<a<<"\tb ="<<b<<endl;return 0;}void swap(int &u,int &v){    int temp = v;v=u;u=temp;}

例13

#include<iostream>using namespace std;long f2(int);long f1(int p){    int k;    long r;    k=p*p;    r=f2(k);return r;}long f2(int q){    long fact = 1;    for(int i=1;i<=q;i++)   fact*=i;    return fact;}int main(){    int i;    long sum=0;    for(i=2;i<=3;i++)    sum+=f1(i);    cout<<"sum ="<<sum<<endl;return 0;}

例14

#include<iostream>#include<cmath>using namespace std;float f(float x);float root(float x1,float x2);float point(float x1,float x2);int main(){    float x1,x2,y1,y2,x;    do{    cout<<"请输入根所在的范围:";cin>>x1>>x2;y1=f(x1);y2=f(x2);cout<<"两端点的值为["<<y1<<","<<y2<<"]"<<endl;}while(y1*y2>=0);x=root(x1,x2);cout<<"在"<<x1<<"与"<<x2<<"之间,方程的解为"<<x<<endl;return 0;   }float f(float x){    return(x*x*x-4*x*x+6*x-10);}float root(float x1,float x2){    float y1,x,y;y1=f(x1);do{    x=point(x1,x2);y=f(x);if(y*y1>0){   y1=y;x1=x;}else x2=x;}while(fabs(y)>=0.0001);    return x;}float point(float x1,float x2){    float y;    y =(x1*f(x2)-x2*f(x1))/(f(x2)-f(x1));return y;}

例15

#include<iostream>using namespace std;float Factorial(int n);int main(){   int a;   float f;   cout<<"input an integer number:";   cin>>a;   f=Factorial(a);   cout<<a<<"!= "<<f<<endl;   return 0;}float Factorial(int n){    float fact;if(n==0)fact=1;elsefact =n*Factorial(n-1);    return fact;}

例16

#include<iostream>using namespace std;const N=8;long fibo(int n);int main(){   long f=fibo(N);   cout<<"Fibonacci数列第8项的值为:"<<f<<endl;   return 0;}long fibo(int n){   if(n==1)return 1L;   else if(n==2)return 1L;   else   return fibo(n-1)+fibo(n-2);}

例17

#include<iostream>using namespace std;int i;int main(){   i=5;   {      int i;  i=7;          cout<<"内层i ="<<i<<endl;   }    cout<<"外层i ="<<i<<endl;   return 0;}

例18

#include<iostream>using namespace std;int i=1;int main()                  {    cout<<"i= "<<i<<endl;int i=5;    cout<<"i= "<<i<<endl;    {   int i=7;   cout<<"i= "<<i<<endl;   cout<<"i= "<<::i<<endl;}cout<<"i= "<<i<<endl;cout<<"i= "<<::i<<endl;return 0;}

例19

#include<iostream>using namespace std;int max(int x,int y){    int z;z=x>y?x:y;return z;}int main(){   extern int a,b;   cout<<max(a,b)<<endl;   return 0;}int a=13,b=-8;

例20

#include<iostream>using namespace std;void sort(int);void echoa();int a[5] = {6,3,9,8,2};int main(){    echoa();sort(5);echoa();    return 0;}void echoa(){    for(int i=0;i<5;i++)cout<<a[i]<<'\t';cout<<endl;}void sort(int n){    int i,j,min,temp;for(i=0;i<n-1;i++){   min=1;   for(j=i+1;j<n;j++)   if(a[j]<a[min])   min=j;   temp=a[i];a[i]=a[min];a[min]=temp;}}

例21

#include<iostream>using namespace std;int a=3,b=5;int main(){   int a=8;   int c;   c=a>b?a:b;   cout<<c<<endl;   return 0;}

例22

#include<iostream>using namespace std;int f(int a){   auto int b=0;   static int c=3;   b++;   c++;   return (a+b+c);}int main(){    int a=2,i;for(i=0;i<3;i++)   cout<<f(a)<<endl;return 0;}

例23

#include<iostream>using namespace std;int fun(int);int main(){    int i,k;cout<<"请输入一个非负整数:";cin>>k;for(i=1;i<=k;i++)cout<<i<<"!="<<fun(i)<<endl;return 0;}int fun(int n){    static int f=1;    f=f*n;    return f;}

例24

#include<iostream>using namespace std;int fun(int);int main(){    int i,k;cout<<"请输入一个非负整数:";cin>>k;for(i=1;i<=k;i++)cout<<i<<"!= "<<fun(i)<<endl;return 0;}int fun(int n){    register int i,f=1;for(i=1;i<=n;i++)f=f*i;return f;}

例25

#include<iostream>using namespace std;int a;int power(int n);int main(){    int b=3,c,d,m;cout<<"enter a and m:"<<endl;cin>>a>>m;c=a*b;cout<<"a= "<<a<<"\tb= "<<b<<"\tc= "<<c<<endl;d=power(m);cout<<"a= "<<a<<"\tm= "<<b<<"\td= "<<d<<endl;return 0;}extern int a;int power(int n){    int i,y=1;for(i=1;i<=n;i++)y*=a;    return y;}

2.编程实现课本每一个编程习题

习题2

#include<iostream>using namespace std;long intPower(int base,int exponent){    long a=1;int i;for(i=1;i<=exponent;i++)a*=base;return a;}int main(){    int base,exponent;cout<<"请输入一个数:"<<endl;cin>>base;cout<<"请输入它的指数:"<<endl;cin>>exponent;cout<<endl;cout<<"这个数的幂为:"<<intPower(base,exponent)<<endl;;return 0;}

习题3

#include<iostream>using namespace std;int sushu(int x){int i,j=1;for(i=2;i<x/2&&j==1;i++)if(x%i==0)j=0;return j;}int main(){int n;cout<<"请输入一个正整数:";cin>>n;if(n<=0)cout<<"输入的不是正整数"<<endl;else if(n==1||n==4)cout<<"这个数不是素数"<<endl;else if(n==2||sushu(n))cout<<"这个数是素数"<<endl;elsecout<<"这个数不是素数"<<endl;return 0;}

习题4