I'm trying to find, reverse, and replace a word inside a sentence. Word and sentence are free to change. We can write them manually or the user can write them.
In main() I cannot access and take the output of the reversing function. Compiler does not give any error but it also does not show any output.
I am not allowed to use any library other than <stdio.h>. What should I do?
#include <stdio.h>
int stringLength(char string[100]) {
int i, l = 0;
for (i = 0; string[i] != '\0'; i ) {
l ;
}
int length = l;
return length;
}
char reversing(char *givenWord[]) {
int i = 0, j = 0, k = 0;
char temp;
j = stringLength(*givenWord) - 1;
while (i < j) {
temp = *givenWord[i];
*givenWord[i] = givenWord[j];
*givenWord[j] = temp;
i ;
j--;
}
return *givenWord;
}
int compare(char *x, char *y) {
while (*x != '\0' || *y != '\0') {
if (*x == *y) {
x ;
y ;
}
// if they are not equal
else
if ((*x == '\0' && *y != '\0') || (*x != '\0' && *y == '\0') ||
*x != *y) {
return 0;
}
}
return 1;
}
int lenght(char *a) {
char *b;
for (b = a; *a; a )
;
return a - b;
}
char *substring(char *main_string, char *substring) {
while (*main_string != '\0') {
char *p = main_string;
char *q = substring;
while (*p == *q ) {
if (*p == ' ' || *p == '\0')
if (*q == '\0') {
return main_string;
}
}
main_string ;
}
return NULL;
}
void replace_string_add(char *s, char *change_what, char *into_what, int shift)
{
char *i_pointer = into_what;
char *c_pointer = change_what;
char *position = substring(s, change_what);
while (position != NULL) {
char *end = position;
while (*end != '\0') {
end ;
}
while (end > position) {
*(end shift) = *end;
end--;
}
while (*into_what != '\0') {
*position = *into_what ;
}
position = substring(s, change_what);
into_what = i_pointer;
change_what = c_pointer;
}
}
void replace_string_remove(char *s, char *change_what, char *into_what,
int shift)
{
char *i_pointer = into_what;
char *c_pointer = change_what;
char *position = substring(s, change_what);
while (position != NULL) {
char *temp = position;
while (*(temp shift) != '\0') {
*temp = *(temp shift);
temp ;
}
*temp = '\0';
while (*into_what != '\0') {
*position = *into_what ;
}
position = substring(s, change_what);
into_what = i_pointer;
change_what = c_pointer;
}
}
void replace_string(char *s, char *change_what, char *into_what)
{
int shift = lenght(into_what) - lenght(change_what);
if (compare(change_what, into_what) == 0) {
if (shift >= 0) {
replace_string_add(s, change_what, into_what, shift);
} else {
replace_string_remove(s, change_what, into_what, -shift);
}
}
}
int main() {
char s[] = "This is the input sentence", change_what[] = "input";
reversing(change_what);
char *word = reversing(change_what);
char into_what = ("%s", word);
replace_string(s, change_what, &into_what);
printf("\"%s\"", s);
return 0;
}
I tried to add other strings and declare them as the reverse function's output.
CodePudding user response：
I believe this code solves your problem. There are comments in the functions and sorry for my bad english
#include <stdio.h>
void put_word(char *word, char *sentence, int index)
{
// Replace the chars of the sentence with the chars of
// the word through the index
// Two counter, one for sentence, other for word
for (int i = index, c = 0; word[c] != '\0'; i , c )
{
sentence[i] = word[c];
}
return;
}
void reverse_word(char *word)
{
int size = 0;
for (int i = 0; word[i] != '\0'; i ) {size ;} // Size of the word
char tmp;
for (int i = 0; i < size / 2; i ) // string mirroring
{
tmp = word[i];
word[i] = word[size -(i 1)]; // 1 is for ignore \0
word[size - (i 1)] = tmp;
}
return;
}
int find_word(char *word, char *sentence)
{
// Return index of the start of the word in sentence
int counter = 0;
for (int i = 0; sentence[i] != '\0'; i ) // Stop at the end of the sentence
{
// If both sentence[i] and word[counter] == '\0' so this is
// should return because of this have the word[counter] != '\0'
if (sentence[i] == word[counter] && word[counter] != '\0')
{
counter ; // Iterate over word
}
else if (counter != 0) // Two options, or word is founded or not
{
if (word[counter] == '\0') // Indicates of the found point
{
return i - counter; // Basic math
}
counter = 0; // If not founded reset counter word
}
}
return -1; // Not found
}
int main()
{
char s[] = "This is the input sentence";
char change_what[] = "input";
int index = find_word(change_what, s);
if (index == -1)
{
printf("Word %s not found!\n", change_what);
return 1;
}
// As these functions work with pointers, the return is not necessary.
reverse_word(change_what);
put_word(change_what, s, index);
printf("\"%s\"", s);
return 0;
}
CodePudding user response：
Your code is much too complicated:
you should functions to:
- compute the length of a string
- find a substring inside another string
- reverse a substring
then in the
mainfunction, you should read a sentence and a word, perform the replacement and output the modified sentence.
Here is a simplified version:
#include <stdio.h>
int string_length(const char *str) {
int len;
for (len = 0; str[len] != '\0'; len )
continue;
return len;
}
void string_reverse(char *str, int from, int len) {
int i = from, j = from len - 1;
while (i < j) {
char c = str[i];
str[i] = str[j];
str[j] = c;
i ;
j--;
}
}
int string_find(const char *s1, const char *s2, in len) {
int i;
if (len == 0)
return 0;
for (i = 0; s1[i] != '\0'; i ) {
for (j = 0;; j ) {
if (j == len) {
// found substring, return start index
return i;
if (s1[i j] != s2[j])
break;
}
}
return -1;
}
int main() {
// sentence and word could be read from the user.
// Use immediate strings for testing
char sentence[] = "This is the input sentence";
char word[] = "input";
int length = string_length(word);
int index = string_find(sentence, word, length);
if (index >= 0) {
string_reverse(sentence, index, length);
}
printf("%s\n", sentence);
return 0;
}