C++作业

c.cpp

//1
#include <iostream>

using namespace std;

int main()
{
    int in;
    cin>>in;
    if(in>=1000||in<0)
        cout<<"invalid input!";
    else
    {
        int digit,hundred,ten,one;
        hundred=in/100;
        ten=in/10%10;
        one=in-100*hundred-10*ten;
        cout<<hundred<<"*100+"
            <<ten<<"*10+"
            <<one<<"*1";
        digit=(in/100!=0)+(in/10!=0)+(in!=0);
        cout<<"\ndigit:"<<digit;
    }
    cout<<endl;
    return 0;
}
//2
#include <iostream>

using namespace std;

int main()
{
    char in;
    cin>>in;
    switch(in)
    {
    case 'A':
        cout<<"90以上";
        break;
    case 'B':
        cout<<"80-90";
        break;
    case 'C':
        cout<<"70-80";
        break;
    case 'D':
        cout<<"60-70";
        break;
    case 'E':
        cout<<"60以下";
        break;
    default:
        cout<<"其他";
    }
    return 0;
}
//3
#include <iostream>
#include <cmath>

using namespace std;

int main()
{
    for(int i=100; i<1000; i++)
        //为Code::Blocks 17.12自带编译器的bug(不出407)做出了优化
        if(i==(int)(pow(i/100,3)+pow(i/10%10,3)+pow(i%10,3)))
            cout<<i<<endl;
    return 0;
}
//4
#include <iostream>

void repeat_output(char ch,int i)
{
    for(int x=0; x<i; x++)
        std::cout<<ch;
}

void a_line(int i,int j)
{
    repeat_output(' ',i-j);
    repeat_output('*',2*j-1);
    std::cout<<'\n';
}

int main()
{
    for(;;)
    {
        int i,j;
        std::cin>>i;
        if(i<0)
            break;
        for(j=1; j<i+1; j++)
            a_line(i,j);
        for(j-=2; j>0; j--)
            a_line(i,j);
    }
    return 0;
}
//自由项目1
#include <iostream>

using namespace std;

int main()
{
    int i;
    cin>>i;
    int count=0;
    for(int x=2; x<=i; x++)
    {
        int c=0;
        for(int y=1; y<=x; y++)
            if(x%y==0&&!(y>x/y))
                c++;
        if(c==1)
        {
            count++;
            cout<<count<<':'<<x<<endl;
        }
    }
    return 0;
}
//5
#include <iostream>

using namespace std;

int main()
{
    int s = 0;
    for (int ps = 1; ps <= 10; ps++)
    {
        int ms = 1;
        for (int i = 1; i <= ps; i++)
            ms *= i;
        s += ms;
    }
    cout << s;
    return 0;
}
//5（同学做的正常版本，不应该双for的。。。）
#include <iostream>
using namespace std;
int main()
{
    int i=1,s=1,sum=0;
    for (; i<=10; i++)
    {
        s*=i;
        sum+=s;
    }
    cout<<sum<<endl;
    return 0;
}
//6
#include <iostream>

using namespace std;

int main()
{
    int in;
    cout<<"prime check:";
    cin>>in;
    int fl=0;
    for(int f=1; f<=in; f++)
        if(in%f==0&&!(f>in/f))
            fl++;
    if(fl==1)
        cout<<in<<" is A prime"<<endl;
    else
        cout<<in<<" is NOT a prime"<<endl;
    return 0;
}
//课堂作业1
#include <iostream>
using namespace std;
int main()
{
    int i;
    cin>>i;
    if(i<0||1>100)
        cout<<"Invalid input!";
    else if(i>=90)
        cout<<"A";
    else if(i>=80)
        cout<<"B";
    else if(i>=70)
        cout<<"C";
    else if(i>=60)
        cout<<"D";
    else
        cout<<"E";
    return 0;
}
//课堂作业1(另)
#include <iostream>
using namespace std;
int main()
{
    int i;
    cin>>i;
    switch((int)i/10)
    {
    case 9:
        cout<<"A";
        break;
    case 8:
        cout<<"B";
        break;
    case 7:
        cout<<"C";
        break;
    case 6:
        cout<<"D";
        break;
    default:
        cout<<"E";
    }
    return 0;
}
//课堂作业2
#include <iostream>
using namespace std;
int main()
{
    int line_num;
    cin>>line_num;
    for(int i=1; i<=line_num; i++)
    {
        for(int j=line_num-i; j>=1; j--)
            cout<<' ';
        for(int k=1; k<=2*i-1; k++)
            cout<<'*';
        cout<<endl;
    }
    return 0;
}
//课堂作业3
#include <iostream>
using namespace std;
int main()
{
    int n=1,c=10;
    do
    {
        n=2*(n+1);
        c--;
    }
    while(c!=1);
    cout<<n;
    return 0;
}
//课堂作业4
#include <iostream>
using namespace std;

int main()
{
    int a,n;
    cin>>a>>n;
    int r=0;
    for(int x=1; x<=n; x++)
    {
        int b=a,v=a;
        for(int i=1; i<x; i++)
        {
            v*=10;
            b+=v;
        }
        r+=b;
    }
    cout<<r;
    return 0;
}
//课堂作业4(另)
#include <iostream>
using namespace std;
int main()
{
    int a,n,i=1,sn=0,tn=0;
    cin>>a>>n;
    while(i<=n)
    {
        tn+=a;
        sn+=tn;
        a*=10;
        ++i;
    }
    cout<<sn;
    return 0;
}
//7
#include <iostream>
#include <iomanip>
using namespace std;
int main()
{
    int i[10] = {2, 3, 5, 7, 11, 101, 131, 151, 181, 191}
                ,c = 5;
    while (c)
    {
        cout<<setw(4) << i[5 - c];
        c--;
    }
    cout << endl;
    while (c < 5)
    {
        cout <<setw(4)<< i[5 + c];
        c++;
    }
    return 0;
}
//8
#include <iostream>
using namespace std;
int main()
{
    int i[5][5] = {    2,    3,    5,    7,   11,
                       101,  131,  151,  181,  191,
                       313,  353,  373,  383,  727,
                       757,  787,  797,  919,  929,
                       10301,10501,10601,11311,11411
                  },
                  s = 0;
    for (int x = 0; x < 5; ++x)
        s += i[x][x];
    cout << s;
    return 0;
}
//自由项目2
#include <iostream>
#include <stdlib.h>
using namespace std;
int main()
{
	system("color 1F");
	int i[10] = { 2,3,5,7,11,13,17,19,23,29 };
	for (int n = 0; n < sizeof(i) / sizeof(int); n++)
		cout << &i[n] << ':' << *(i + n) << endl;
	return 0;
}
//课堂作业5
#include <iostream>
using namespace std;
int main()
{
    int a[9][9]= {};
    for(int i=0; i<9; i++)
        a[i][i]=1;
    for(int i=0; i<9; i++)
    {
        for(int j=0; j<9; j++)
            cout<<a[i][j];
        cout<<endl;
    }
}
//课堂作业6
#include <iostream>
using namespace std;
int main()
{
    int ip[4][5]= {};
    for(int i=0; i<4; i++)
        for(int j=0; j<5; j++)
            cin>>ip[i][j];
    for(int i=0; i<4; i++)
        for(int j=0; j<5; j++)
            if(ip[i][j]<0)
                cout<<i+1<<','<<j+1<<':'<<ip[i][j]<<" <0"<<endl;
}
//课堂作业6(改题目)
#include <iostream>
#include <climits>
using namespace std;
int main()
{
    int ip[4][5]= {};
    for(int i=0; i<4; i++)
        for(int j=0; j<5; j++)
            cin>>ip[i][j];
    int x=INT_MIN,mi=0,mj=0;
    for(int i=0; i<4; i++)
        for(int j=0; j<5; j++)
            if(x<ip[i][j])
            {
                x=ip[i][j];
                mi=i;
                mj=j;
            }
    cout<<mi+1<<','<<mj+1<<':'<<x<<" max"<<endl;
}
//课堂作业7
#include <iostream>
using namespace std;
int main()
{
    int i[7]= {1,4,6,2,5,7,3};
    for(int d=0; d<5; d++)
        for(int c=0,tmp; c<6; c++)
        {
            if(i[c+1]<i[c])
            {
                tmp=i[c];
                i[c]=i[c+1];
                i[c+1]=tmp;
            }
        }
    for(int n=0; n<7; n++)
        cout<<i[n];
}
//课堂作业8
#include <iostream>
using namespace std;
int main()
{
    int ixi;
    cout<<"?x?:";
    cin>>ixi;
    int ip[ixi][ixi]= {};
    for(int i=0; i<ixi; i++)
        for(int j=0; j<ixi; j++)
            cin>>ip[i][j];
    int sum=0;
    for(int i=0; i<ixi; i++)
        sum+=ip[0][i];
    for(int i=1,x=0; i<ixi; i++)
    {
        for(int j=0; j<ixi; j++)
            x+=ip[i][j];
        if(x!=sum)
            return -1;
        x=0;
    }
    for(int i=0,x=0; i<ixi; i++)
    {
        for(int j=0; j<ixi; j++)
            x+=ip[j][i];
        if(x!=sum)
            return -2;
        x=0;
    }
    int u=0;
    for(int i=0; i<ixi; i++)
        u+=ip[i][i];
    if(u!=sum)
        return -3;
    u=0;
    for(int i=0; i<ixi; i++)
        u+=ip[i][ixi-i-1];
    if(u!=sum)
        return -4;
    return 0;
}
//9
//不能用VC6.0编译，但可以用codeblocks编译
#include <iomanip>
#include <iostream>
using namespace std;
int main()
{
    int	w=6;
    int	c;
    cin>>c;
    int m[c][c]= {};
    for (int i=0; i<c; i++)
        m[i][0]=1;
    for (int y=1; y<c; y++)
        for (int x=1; x<c; x++)
            m[y][x]=m[y-1][x-1]+m[y-1][x];
    for (int y=0; y<c; y++)
    {
        for (int x=0; x<c; x++)
            if (m[y][x]!=0)
                cout<<setw(w)<< m[y][x];
        cout<<endl;
    }
    return 0;
}
//9（修改，顺便记录以下VS2017以及VC需要注意的）
//VS2017编译用库
//#include "stdafx.h"
#include <iomanip>
#include <cmath>
#include <iostream>
using namespace std;
int main()
{
	/*VC6没有变量作用域的概念，在不同域中定义重名变量也会出现redefinition错误。这非常
	糟糕，不得不将所有要用的变量一块定义，且都可以全局访问，容易引起混淆，很不方便。*/
	//坐等老师讲到类和对象引入权限修饰符
	int w, c, x, y;
	cin >> c;
	if (c < 1)
		return -1;
	//直接定义动态数组只在codeblocks可用，这里用指针数组
	//int m[c][c]= {};
	int **m = new int*[c];
	for (x = 0; x < c; x++)
		m[x] = new int[c];
	//也不能直接赋空值，通过循环实现填充0
	//m= {};
	for (y = 0; y < c; y++)
		for (x = 0; x < c; x++)
			m[y][x] = 0;
	//首列填充1，作为计算的基础
	for (x = 0; x < c; x++)
		m[x][0] = 1;
	//通过相对位置（上一行和列以及同列上一行的值的和）取值
	for (y = 1; y < c; y++)
		for (x = 1; x < c; x++)
			m[y][x] = m[y - 1][x - 1] + m[y - 1][x];
	/*取最大值（底部中间）用来设置最佳行宽
	至少间隔一格*/
	w = log10(m[c - 1][c / 2]) + 2;
	//输出（不输出0）
	for (y = 0; y < c; y++)
	{
		for (x = 0; x < c; x++)
			if (m[y][x] != 0)
				cout << setw(w) << m[y][x];
		cout << endl;
	}
	//释放指针
	for (x = 0; x < c; x++)
		delete[] m[x];
	delete[] m;
	//在VS2017上暂停
	cin.get();
	cin.get();
	return 0;
}
//10
#include <iostream>

using namespace std;

void factor_output(int);

int main()
{
    int ip;
    cin>>ip;
    factor_output(ip);
}

void factor_output(int ip)
{
    for(int i=1; i<=ip; i++)
        if(ip%i==0)
            cout<<i<<' ';
}
//课堂作业9
#include <iostream>
using namespace std;
int main()
{
    char c;
    cin>>c;
    char ca[128];
    int i;
    for(i=-1; i<2; i++)
        ca[i+1]=(char)(c+i);
    for(i=0; i<3; i++)
    {
        switch(ca[i])
        {
        case 96:
            ca[i]='z';
            break;
        case 123:
            ca[i]='a';
            break;
        case 64:
            ca[i]='Z';
            break;
        case 91:
            ca[i]='A';
            break;
        }
        cout<<ca[i]<<endl;
    }
    return 0;
}
//课堂作业10
#include <iostream>
using namespace std;
int main()
{
    char c[10000],cc[10000],s;
    int ws,p,i;
    cin>>ws>>p>>s;
    if(p>ws)
        return -1;
    for(i=0; i<ws; i++)
        cin>>c[i];
    for(i=0; i<p; i++)
        cc[i]=c[i];
    cc[p]=s;
    for(i=p; i<ws+1; i++)
        cc[i+1]=c[i];
    for(i=0; i<ws+1; i++)
        cout<<cc[i];
    return 0;
}
//课堂作业11
#include <iostream>
using namespace std;

int string_length(char[]);

int main()
{
    char c[]="qwertyuiopasdfghjklzxcvbnm";
    cout<<string_length(c);
    return 0;
}

/**
取字符串长度

@param char[] 待测量的字符串
@return 长度
*/
int string_length(char c[])
{
    int i=0;
    while(c[i]!='\0')
        i++;
    return i;
}
//课堂作业12
#include <climits>
#include <iostream>
using namespace std;
int min_val(int ip[],int n)
{
    int tmp=INT_MAX;
    for(int c=0; c<n; c++)
        if(ip[c]<tmp)
            tmp=ip[c];
    return tmp;
}
int main()
{
    int i[]={435,2345,567,123,-324,34,45},len=sizeof(i)/sizeof(int);
    cout<<min_val(i,len);
    return 0;
}
//课堂13
#include <iostream>
using namespace std;
bool range_test(int,int,int);
int main()
{
    int i,a,b;
    cin>>i>>a>>b;
    cout<<range_test(i,a,b);
    return 0;
}
bool range_test(int val,int low,int high)
{
    if(val>=low&&val<=high)
        return true;
    return false;
}
//课堂14
#include <iostream>
using namespace std;
int words_num(char[]);
int main()
{
    char ip[10000]="alpha beta  gamma   delta  epsilon     zeta";
    cout<<words_num(ip);
    return 0;
}
int words_num(char ch[])
{
    int len=0;
    while(ch[len]!='\0')
        len++;
    int i=0,c=1,status=0;
    for(; i<len-1; i++)
    {
        if(ch[i]==' ')
            status=1;
        if(ch[i]!=' '&&status==1)
        {
            c++;
            status=0;
        }
    }
    return c;
}
//11
#include <climits>
#include <iostream>
using namespace std;
int max_val(int ip[],int n)
{
    int tmp=INT_MIN;
    for(int c=0; c<n; c++)
        if(ip[c]>tmp)
            tmp=ip[c];
    return tmp;
}
int main()
{
    int i[]={435,2345,567,123,-324,34,45},len=sizeof(i)/sizeof(int);
    cout<<max_val(i,len);
    return 0;
}
//12
#include <iostream>
using namespace std;
class Box
{
    int length;
    int width;
    int height;
public:
    Box()
    {
        length=0;
        width=0;
        height=0;
    };
    Box(int _length,int _width,int _height)
    {
        length=_length;
        width=_width;
        height=_height;
    };
    int volume()
    {
        return length*width*height;
    }
};
int main()
{
    Box b=Box(12,20,25);
    cout<<b.volume();
    return 0;
}
//13
#include <iostream>
using namespace std;
//Obj statement
class student
{
    int id;
    int mark;
public:
    student(int id,int mark);
    void show();
};
//Obj definition
student::student(int id,int mark)
{
    (*this).id=id;
    this->mark=mark;
}
void student::show()
{
    cout<<"id:"<<id<<endl<<"mark:"<<mark<<endl;
}
//Main
int main()
{
    //Initialize obj array and memory address.
    student s[5]=
    {
        student(1,2),
        student(2,4),
        student(3,6),
        student(4,8),
        student(5,10),
    },*p=s;
    //Output
    for(int i=0; i<3; i++)
        (p+i*2)->show();
}