Summary of embedded written test questions

Summary of embedded written test questions

1. Sort a string in reverse order

# Include <iostream> <br/> using namespace STD; <br/> // # define null (void *) 0) <br/> char * mystrrev (char * const DEST, const char * const SRC) <br/>{< br/> If (DEST = NULL & src = NULL) <br/> return NULL; <br/> char * ADDR = DEST; <br/> int val_len = strlen (SRC); <br/> Dest [val_len] = '/0'; <br/> int I; <br/> for (I = 0; I <val_len; I ++) <br/> {<br/> * (DEST + I) = * (SRC + val_len-i-1); <br/>}< br/> return ADDR; </P> <p >}< br/> main () <br/>{< br/> char * STR = "asdfa"; <br/> char * str1 = NULL; <br/> str1 = (char *) malloc (20); <br/> If (str1 = NULL) <br/> cout <"malloc failed"; <br/> cout <mystrrev (str1, str); <br/> free (str1); <br/> str1 = NULL; // eliminates wild pointers <br/>}
2. Sort a linked list in reverse order

# Include <stdio. h> <br/> # include <ctype. h> <br/> # include <stdlib. h> <br/> typedef struct list {<br/> int data; <br/> struct list * Next; <br/>} List; <br/> list * list_create (void) <br/>{< br/> struct list * head, * tail, * P; <br/> int e; <br/> head = (list *) malloc (sizeof (list); <br/> tail = head; <br/> printf ("/NLIST create, input numbers (end of 0): "); <br/> scanf (" % d ", & E); <br/> while (E) {<br/> P = (list *) malloc (sizeof (List); <br/> P-> DATA = E; <br/> tail-> next = P; <br/> tail = P; <br/> scanf ("% d", & E) ;}< br/> tail-> next = NULL; <br/> return head; <br/>}< br/> list * list_reverse (list * head) // core code <br/>{< br/> list * P, * q, * R; <br/> P = head; <br/> q = p-> next; <br/> while (Q! = NULL) <br/>{< br/> r = Q-> next; <br/> q-> next = P; <br/> P = Q; <br/> q = r; <br/>}< br/> head-> next = NULL; <br/> head = P; <br/> return head; <br/>}< br/> void main (void) <br/>{< br/> struct list * head, * P; <br/> int D; <br/> head = list_create (); <br/> printf ("/N"); <br/> for (P = head-> next; P; P = p-> next) <br/> printf ("-- % d --", p-> data); <br/> head = list_reverse (head ); <br/> printf ("/N"); <br/> for (P = head; P-> next; P = p-> next) <br/> printf ("-- % d --", p-> data); <br/>}
3. Calculate the number of bits in a byte to be set to 1.

# Receivede <iostream> <br/> # define N 10 <br/> // defines the byte type alias <br/> # ifndef byte <br/> typedef unsigned char byte; <br/> # endif <br/> int comb (byte B [], int N) <br/> {<br/> int COUNT = 0; <br/> int Bi, BJ; <br/> byte cc = 1, TT; <br/> // obtain the byte data from the first bi record <br/> for (Bi = 0; Bi <n; Bi ++) <br/>{< br/> // calculate the number of 1 in the eight bits of the byte. <br/> TT = B [bi]; <br/> for (bj = 0; BJ <8; BJ ++) <br/> {<br/> // is the result of Phase 1 or Mode 2 1 1 1? Test whether the current BIT is 1 <br/> // If (TT % 2 = 1) <br/> If (TT & CC) = 1) <br/>{< br/> count ++; <br/>}< br/> // shifts one or two places to the right, same effect <br/> // TT = tt> 1; <br/> TT = TT/2; <br/>}< br/> return count; <br/>}< br/> // test <br/> int main () <br/> {<br/> byte B [10] = {,}; <br/> cout <comb (B, n) <Endl; <br/> return 0; <br/>}
4. Search for a given byte)
5. Find the longest possible substring in a string

Char * search (char * cpsource, char ch) <br/>{< br/> char * cptemp = NULL, * cpdest = NULL; <br/> int itemp, icount = 0; <br/> while (* cpsource) <br/> {<br/> If (* cpsource = CH) <br/> {<br/> itemp = 0; <br/> cptemp = cpsource; <br/> while (* cpsource = CH) <br/> ++ itemp, ++ cpsource; <br/> If (itemp> icount) <br/> icount = itemp, cpdest = cptemp; <br/> If (! * Cpsource) <br/> break; <br/>}< br/> + + cpsource; <br/>}< br/> return cpdest; <br/>}
6. convert a string to an integer

Int myatoi (char STR []) <br/>{< br/> int I; <br/> int Weight = 1; // weight <br/> int RTN = 0; // return value <br/> for (I = strlen (STR)-1; I> = 0; I --) <br/> {<br/> RTN + = (STR [I]-'0') * weight; // <br/> weight * = 10; // weight gain <br/>}< br/> return RTN; <br/>}< br/> void main () <br/>{< br/> char STR [32]; <br/> printf ("input a string:"); <br/> gets (STR ); <br/> printf ("% d/N", myatoi (STR); <br/>}
7. Convert Integers to strings

# Include <stdio. h> <br/> # include <string. h> <br/> void reverse (char s []) <br/> {// string inversion <br/> int C, I = 0, J; <br/> for (j = strlen (S)-1; I <j; j --) <br/> {c = s [I]; <br/> S [I] = s [J]; <br/> S [J] = C; <br/> I ++; <br/>}< br/> void integertostring (char s [], int N) <br/> {int I = 0, sign; <br/> If (Sign = N) <0) // if it is a negative number, first convert it to a positive number <br/> N =-N; <br/> do // changes from a single bit to a character until the maximum bit. <br/> {s [I ++] = n % 10 + '0' should be reversed '; <br/>}while (n = N/10)> 0); <br/> // if it is a negative number, add a negative number. <br/> If (sign <0) <br/> S [I ++] = '-'; <br/> S [I] = '/0 '; // string ends <br/> reverse (s); <br/>}< br/> void main () <br/> {int m; <br/> char C [100]; <br/> printf ("enter an integer m:"); <br/> scanf ("% d", & M ); <br/> integertostring (C, M); <br/> printf ("integer = % d string = % s/n", M, c); <br/>}