嵌入式相关笔试题目汇总

嵌入式相关笔试题目汇总

#include <iostream>
using namespace std;
//#define NULL ((void *)0)
char * mystrrev(char * const dest,const char * const src)
{
if (dest==NULL && src==NULL)
return NULL;
char *addr = dest;
int val_len = strlen(src);
dest[val_len] = '/0';
int i;
for (i=0; i<val_len; i++)
{
*(dest+i) = *(src+val_len-i-1);
}
return addr;

}
main()
{
char *str="asdfa";
char *str1=NULL;
str1 = (char *)malloc(20);
if (str1 == NULL)
cout<<"malloc failed";
cout<<mystrrev(str1,str);
free(str1);
str1=NULL;//杜绝野指针
}

#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
typedef struct List{
int data;
struct List *next;
}List;
List *list_create(void)
{
struct List *head,*tail,*p;
int e;
head=(List *)malloc(sizeof(List));
tail=head;
printf("/nList Create,input numbers(end of 0):");
scanf("%d",&e);
while(e){
p=(List *)malloc(sizeof(List));
p->data=e;
tail->next=p;
tail=p;
scanf("%d",&e);}
tail->next=NULL;
return head;
}
List *list_reverse(List *head)//核心代码
{
List *p,*q,*r;
p=head;
q=p->next;
while(q!=NULL)
{
r=q->next;
q->next=p;
p=q;
q=r;
}
head->next=NULL;
head=p;
return head;
}
void main(void)
{
struct List *head,*p;
int d;
head=list_create();
printf("/n");
for(p=head->next;p;p=p->next)
printf("--%d--",p->data);
head=list_reverse(head);
printf("/n");
for(p=head;p->next;p=p->next)
printf("--%d--",p->data);
}

#incluede<iostream>
#define N 10
//定义BYTE类型别名
#ifndef BYTE
typedef unsigned char BYTE;
#endif
int comb(BYTE b[],int n)
{
int count=0;
int bi,bj;
BYTE cc=1,tt;
//历遍到第bi个BYTE数据
for(bi=0;bi<n;bi++)
{
//计算该BYTE的8个bit中有多少个1
tt=b[bi];
for(bj=0;bj<8;bj++)
{
//与1相与或模2结果是否是1？测试当前bit是否为1
//if(tt%2==1)
if((tt&cc)==1)
{
count++;
}
//右移一位或除以2，效果相同
//tt=tt>>1;
tt=tt/2;
}
}
return count;
}
//测试
int main()
{
BYTE b[10]={3,3,3,11,1,1,1,1,1,1};
cout<<comb(b,N)<<endl;
return 0;
}

char * search(char *cpSource, char ch)
{
char *cpTemp=NULL, *cpDest=NULL;
int iTemp, iCount=0;
while(*cpSource)
{
if(*cpSource == ch)
{
iTemp = 0;
cpTemp = cpSource;
while(*cpSource == ch)
++iTemp, ++cpSource;
if(iTemp > iCount)
iCount = iTemp, cpDest = cpTemp;
if(!*cpSource)
break;
}
++cpSource;
}
return cpDest;
}

int MyAtoI(char str[])
{
int i;
int weight = 1; // 权重
int rtn = 0; // 用作返回
for(i = strlen(str) - 1; i >= 0; i--)
{
rtn += (str[i] - '0')* weight; //
weight *= 10; // 增重
}
return rtn;
}
void main()
{
char str[32];
printf("Input a string :");
gets(str);
printf("%d/n", MyAtoI(str));
}

#include<stdio.h>
#include<string.h>
void reverse(char s[])
{   //字符串反转
int c, i=0, j;
for(j=strlen(s)-1;i<j;j--)
{    c=s[i];
s[i]=s[j];
s[j]=c;
i++;
}
}
void IntegerToString(char s[],int n)
{    int i=0,sign;
if((sign=n)<0)//如果是负数，先转成正数
n=-n;
do //从个位开始变成字符,直到最高位,最后应该反转
{    s[i++]=n%10+'0';
}while((n=n/10)>0);
//如果是负数，补上负号
if(sign<0)
s[i++]='-';
s[i]='/0';//字符串结束
reverse(s);
}
void main()
{    int m;
char c[100];
printf("请输入整数m: ");
scanf("%d",&m);
IntegerToString(c,m);
printf("integer = %d string = %s/n", m, c);
}