c和c++下用栈实现数的进制转换
1. C的实现
//stack.h
#ifndef STACK_H
#define STACK_H
#define STACK_CAPACITY 20//maximum size of stack
typedef int stackEle;
typedef struct
{
stackEle myArray[ STACK_CAPACITY ];
int myTop;
}stack;
//construct(initialize) an empty stack
stack *stack_init(void);
//return 1 if stack is empty and 0 otherwise
int empty(stack *);
//retrieve top element of the stack
stackEle top(stack* );
//add an element at the top of the stack
void push(stack*,stackEle);
//remove the top element of the stack
void pop(stack* );
#endif
//stack.c
#include <stdio.h>
#include "stack.h"
#include <assert.h>
#include <stdlib.h>
//construct (initialize) an empty stack
stack* stack_init(void)
{
stack* s = (stack*)malloc(sizeof(stack));
assert(s);
s->myTop = -1;//stack is empty
return s;
}
//return 1 if stack is empty and 0 otherwise
int empty(stack *s)
{
assert(s);
if(0 > s->myTop)
return 1;
else
return 0;
}
//retrieve top element of the stack
stackEle top(stack* s)
{
assert(s);
if(0 > s->myTop)
{
printf("Error:stack is empty--no value can be reported\n");
exit(1);
}
return s->myArray[s->myTop];
}
//add an element at the top of the stack
void push(stack* s,stackEle val)
{
assert(s);
s->myTop++;
if(STACK_CAPACITY < s->myTop)//check if overflow
{
printf("Error:stack is full--can't add new value\n");
exit(1);
}
s->myArray[s->myTop] = val;
}
//remove the top element of the stack
void pop(stack* s)
{
assert(s);
if(0 > s->myTop)//check if underflow
{
printf("Error:stack is empty--can't remove a value\n");
exit(1);
}
printf("%d ",s->myArray[s->myTop--]);
}
//do base-10 to base-2 transformation by array-based stack
int main()
{
stack *mystack = stack_init();
int a = 255,b,base = 2;
do
{
b = a % base;
push(mystack,b);
a = a / base;
} while(a != 0);
while(!empty(mystack))
pop(mystack);
相关文档:
【实现功能】:Linux下的C编程:编写一个程序(库),实现定时器(计时器)的功能,它能为用户提供在同一进程中多次使用的定时器。这里要求用信号来实现。
【解题思路】:编写一个结构体Timer代表一个计时器,然后再定义Timer类型的数组myTimer[N],用来保存我们设置的定时器;再定义函数setTimer()生成计时器,并将生成 ......
1.时间表示
在程序当中,我们经常要输出系统当前的时间,比如我们使用date命令的输出结果.这个时候我们可以使用下面两个函数:
#include <sys/time.h>
time_t time(time_t *tloc);
char *ctime(const time_t *clock);
time函数返回从1970年1月1日0 ......
选两个比较有代表性的函数
首先下载安装sdk,将其中的sde.dll,pe.dll和sg.dll拷贝过来
使用如下的代码,指定dll后直接调用其中的函数,
/// <summary>
/// Sets the value for a small integer column.
/// </summary>
[DllImport(".\\sde91.dll", SetLastError = true, ......
一般我们调用shell脚本都用system()来实现,然后发现sytem返回值不好控制而且转换麻烦(还要右移4位即/256),于是我用popen来获取shell的返回值。果然在Unix世界里面,通道就是连结各个方面的桥梁啊!
代码例子如下:
#include<stdio.h>
#include<stdlib.h>
#include<sys/wait.h>
int main (int argc ......