嵌入式软件工程师经典笔试题

为帮助大家巩固嵌入式工程是基础知识，yjbys小编为大家整理最新嵌入式工程师考试题如下：

1、将一个链表逆序

LinkList *reverse(LinkList *head)

{

LinkList *p1,*p2 = NULL,*p3 = NULL;

if(head == NULL || head->next == NULL)

return head;

p1 = head->next;

while(p1!=NULL)

{

p3 = p1->next;

p1->next = p2;

p2 = p1;

p1 = p3;

}

head->next = p2;

// head = p2;

return head;

}

2、计算一个字节里(byte)里面有多少bit被置1

#include

int comb(const int c)

{

int count = 0;

int i = 0;

int cc = c;

while(i++<8)

{

if((cc&1)==1)

{

count++;

}

cc = cc>>1;

}

return count;

}

int main()

{

const int c = 0xcf;

printf("%dn",comb(c));

return 1;

}

3、在一个字符串中找到可能的.最长的子字符串

#include

#include

#include

char *commanstring(char shortstring[],char longstring[])

{

int i,j;

char *substring = malloc(256);

if(strstr(longstring,shortstring)!=NULL)

return shortstring;

for(i=strlen(shortstring)-1;i>0;i--)

{

for(j=0;j<=strlen(shortstring)-i;j++)

{

memcpy(substring,&shortstring[j],i);

substring[i]='';

if(strstr(longstring,substring)!=NULL)

return substring;

}

}

return NULL;

}

void main(void)

{

char *str1 = "aocdfe";

char *str2 = "pmcdfa";

char *comman = NULL;

if(strlen(str1)>strlen(str2))

comman= commanstring(str2,str1);

else

comman = commanstring(str1,str2);

printf("the longest comman string is:%sn",comman);

}

4、字符串转换为整数

#include

#include

void reverse(char s[])

{ //字符串反转

int c, i=0, j;

for(j=strlen(s)-1;i

{ 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]='';//字符串结束

reverse(s);

}

void main()

{ int m;

char c[100];

m =215;

IntegerToString(c,m);

printf("integer = %d string = %sn", m, c);

}

5、整数转换为字符串

#include

#include

int Atoi(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("%dn", Atoi(str));

}

6、将一个字符串逆序

#include

#include

char *strconv(char *p)

{

int length = strlen(p);

char *ptr = p;

char *ptr_1 = p + length -1;

while(ptr < ptr_1)

{

char c = *ptr;

*ptr = *ptr_1;

*ptr_1 = c;

++ptr;

--ptr_1;

}

return p;

}

int main()

{

char str[]="abcdef1234";

char *p;

p = strconv(str);

printf("%s",p);

return 1;

}