c语言函数

用递归法将一个正整数n的各个数字分别输出int f(int num)

{

int x;

if(num==0)

return 0;

else{

x=num%10;

f(num/10);

}

穷举实例

int main()

{

int n=1,m,sum,i;

while(1)

{

m=n;

sum=0;

for(i=1;i<8;i++)

{

m=m*2;

sum=m+sum;

}

sum=sum+n;

if(sum==765)

{

cout<<"fist"<

cout<<"last"<

break;

}

n++;

}

return 0;

}

宏定义可以定义函数例如交换函数swap

#Define swap（a,b）{int c;c=a;a=b;b=c;} 简单结构体成员号码姓名

#include "StdAfx.h"

#include"stdio.h"

#include"string.h"

#include"iostream"

using namespace std;

struct student

{ int num;

char name[50];

struct student *next;

};

struct student *creat(int n)

{

int i;

struct student *head,*p1,*p2;

int num1;

char name1[50];

head=NULL;

for(i=n;i>0;--i)

{

p1=(struct student* )malloc(sizeof(struct student));

cout<<"输入编号";

cin>>num1;

cout<<"输入姓名";

cin>>name1;

p1->num=num1;

strcpy(p1->name,name1);

if(head==NULL)

{

head=p1;

p2=p1;

}

else

{

p2->next=p1;

p2=p1;

}

}p2->next=NULL;

return head;

void main()

{

int n;

struct student *q;

cin>>n;

q=creat(n);

while(q)

{

cout<<"编号"<num<<"\n";

cout<<"姓名"<name<<"\n";

q=q->next;

}

getchar();

}

利用栈实现进制转换

#include "StdAfx.h"

#include

typedef struct tagSTACK {

int stack[255];

int top;

}STACK;

STACK s;

void push(int i)

{

s.top++;

s.stack[s.top] = i;

}

int pop()

{

int ret;

if (s.top> -1)

ret = s.stack[s.top];

s.top--;

return ret;

}

return -1;

}

void Bin(int i, int k, char str[])

{

int j, ret;

while (i)

{

push(i % k);

i /= k;

}

for (j = 0; ret = pop(), ret != -1; ++j) { if (ret > 9)

{

str[j] = ret + 'A' - 10;

}

{

str[j] = ret + '0'; }

}

str[j] = 0;

}

int main(void)

{

int i; int j;

char result[255];

s.top = -1;

printf("Please inuput the Number:"); scanf("%d", &i);

getchar();

printf("Please inuput the mode (2,8,16):"); scanf("%d", &j);

getchar();

switch (j)

{ case 2:

Bin(i, 2, result); printf("二进制:\t\t%s\n", result); s.top = -1; break;

case 8:

s.top = -1; Bin(i, 8, result); printf("八进制:\t\t%s\n", re sult); break;

case 16:

s.top = -1; Bin(i, 16, result); printf("十六进制:\t%s\n", result); break;

}

return 0;

}

递归计算多项式

double f1(int n,int x)

{

if(n==0)

return double(1);

else if(n==1)

return double(2*x);

else if(n>1)

return 2*x*f1(n-1,x)-2*(n-1)*f1(n-2,x); }

double f2(int n,int x)

{

struct STACK

{

int num;

double data ;

}stack[100];

int i,top=0;

double sum1=1,sum2;

sum2=2*x;

for(i=n;i>=2;i--)

{

top--;

stack[top].num=i;

}

while(top>0)

{

stack[top].data=2*x*sum2-2*(stack[top].num-1)*sum1;

sum1=sum2;

sum2=stack[top].data;

top--;

}

return sum2;

}

void main()

{

int x,n;

double sum1,sum2;

cout<<"输入n的值\n";

cin>>n;

cout<<"输入x\n";

cin>>x;

sum1=f1(n,x);

sum2=f1(n,x);

cout<<"递归算出函数\n"<

cout<<"栈递归算出函数\n"<

}

图形化，

#include "stdafx.h"

#include

int main( void )

{

HWND hWnd=GetConsoleWindow();

// 获取一个可供画图的DC，我这里就直接用桌面算了

HDC hdc=GetWindowDC(hWnd);

// 创建红色、1像素宽度的实线画笔

//HPEN hpen1 = CreatePen( PS_SOLID, 1, RGB(255,0,0) );

// 创建绿色、5像素宽度的破折画笔，如果你想创建其他种类的画笔请参阅MSDN

//HPEN hpen2 = CreatePen( PS_DASH, 5, RGB(0,255,0) );

// 创建一个实体蓝色画刷

//HBRUSH hbrush1 = CreateSolidBrush( RGB(0,0,255) );

// 创造一个透明的画刷，如果你想创建其他种类的画刷请参阅MSDN // HBRUSH hbrush2 = (HBRUSH)GetStockObject( NULL_BRUSH );

// 将hpen1和hbrush1选进HDC，并保存HDC原来的画笔和画刷

// HPEN hpen_old = (HPEN)SelectObject( hdc, hpen1 );

// HBRUSH hbrush_old = (HBRUSH)SelectObject( hdc, hbrush1 );

// 在(40,30)处画一个宽200像素，高50像素的矩形

// Rectangle( hdc, 40, 30, 40+200, 30+50 );

// 换hpen1和hbrush1，然后在(40,100)处也画一个矩形，看看有何差别

//SelectObject( hdc, hpen2 );

// SelectObject( hdc, hbrush2 );

//Rectangle( hdc, 40, 100, 40+200, 100+50 );

// 画个椭圆看看

//Ellipse( hdc, 40, 200, 40+200, 200+50 );

// 画个(0,600)到(800,0)的直线看看

// MoveToEx( hdc, 0, 600, NULL );

//LineTo( hdc, 800, 0 );

// 在(700,500)处画个黄点，不过这个点只有一像素大小，你细细的看才能找到

//SetPixel( hdc, 700, 500, RGB(255,255,0) );

// 恢复原来的画笔和画刷

//SelectObject( hdc, hpen_old );

//SelectObject( hdc, hbrush_old );

return 0;

}

颜色

#include "stdafx.h"

#include

#include"iostream"

using namespace std;

int main( void )

{

HANDLE hdc;

hdc = GetStdHandle(STD_OUTPUT_HANDLE);

SetConsoleTextAttribute(hdc,

FOREGROUND_RED |

FOREGROUND_GREEN); cout << "This text is yellow." << endl; SetConsoleTextAttribute(hdc,

FOREGROUND_GREEN |

FOREGROUND_BLUE); cout << "This text is cyan." << endl;

SetConsoleTextAttribute(hdc,

FOREGROUND_BLUE |

FOREGROUND_RED); cout << "This text is magenta." << endl;

SetConsoleTextAttribute(hdc,

FOREGROUND_RED |

FOREGROUND_GREEN |

FOREGROUND_BLUE);

cout << "This text is white." << endl;

return 0;

}

bois time 设置

#include "stdafx.h"

#include

#include"iostream"

using namespace std;

#include"time.h"

void main()

{ time_t now;

time (&now);

cout<

}