seeking combinations (strstr) of letters in external file - c

Question

I have a task to make smth like t9 like it was in old phones (number can also mean some combination of letters). For example, if user run it this way ./t9search 23 < list.txt, program should return numbers which has this combination of digits or letters that corresponds to them (in this case a,b,c and d,e,f). It's also forbidden to work with dynamic memory(malloc, free) and functions with algorithms (qsort, lsearch etc). Format of information in file is "name\n number\n name\n number\n...".
The loop doesn't work correctly but I can't find a mistake. The program should return {Name}, {number}but it return only numbers.
The code is:
`
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define FULFILLED 1
#define NOT_FULFILLED 0
int main(int argc, char **argv)
{
char line[99];
int line_no = -1;
int size = strlen(argv[1]);
char letters[size][5];
int total_combinations = 1;
char combinations[total_combinations][size + 1];
int current_combination[size];
int check_name = NOT_FULFILLED;
char name[99];
for(int i = 0; argv[1][i]; i++)
{
switch(argv[1][i]) //cases according to input
{
case '0':
strcpy(letters[i], "+");
break;
case '2':
strcpy(letters[i], "abc");
break;
case '3':
strcpy(letters[i], "def");
break;
case '4':
strcpy(letters[i], "ghi");
break;
case '5':
strcpy(letters[i], "jkl");
break;
case '6':
strcpy(letters[i], "mno");
break;
case '7':
strcpy(letters[i], "pqrs");
break;
case '8':
strcpy(letters[i], "tuv");
break;
case '9':
strcpy(letters[i], "wxyz");
break;
}
total_combinations *= strlen(letters[i]); //number of combinations of letters from array elements
}
for (int i = 0; i < size; i++)
{
current_combination[i] = 0;
}
int k = 0;
while (k < total_combinations)
{
for (int set_idx = 0; set_idx < size; set_idx++)
{
int letter_idx = current_combination[set_idx];
combinations[k][set_idx] = letters[set_idx][letter_idx];
}
combinations[k][size] = '\0';
for(int i = size - 1; i >= 0; i--)
{
current_combination[i]++;
if (current_combination[i] == strlen(letters[i]))
{
current_combination[i] = 0;
}
else
{
break;
}
}
k++;
}
printf("%c\n", sizeof(combinations)/sizeof(combinations[0]));
while(fgets(line, sizeof(line), stdin))
{
line_no++;
if (line_no % 2 == 0) //even lines (names)
{
name[99] = line; //variable to use name with number
for (int i = 0; i < total_combinations; i++) //for each combination from array with combinations
{
if (strstr(line, combinations[i])) //if combination is a substring of a string
{
check_name = FULFILLED;
}
}
}
else if (line_no % 2 == 1) //odd lines (numbers)
{
if (check_name == FULFILLED || strstr(line, argv[1])) // if there's name that corresponds with input OR input is a substring of a string
{
printf("%s, %s", name, line);
check_name = NOT_FULFILLED;
}
}
}
}
`
I've tried to change the way of checking names:
if (line_no % 2 == 0)
{
for (int j = 0; j <= strlen(letters); j++)
{
char let = getchar();
for (int i = 0; i < strlen(line); i++)
{
if (letters[j] == line[i])
{
check_name = FULFILLED;
continue;
}
else if (letters[j] != line [i])
{
break;
}
}
}
}
Sure I didn't reach success. So I'd be extremely grateful for any help.

Answer 1

Arrays do not resize reflectively when the variables used to create them change. They are sized permanently at the time of their initialization. The following
int total_combinations = 1;
char combinations[total_combinations][size + 1];
/* ... */
total_combinations *= strlen(letters[i]);
does not cause combinations to grow as total_combinations does. Move the definition of combinations to after total_combinations has been fully computed.
The following attempts to assign a char * to a char, and also indexes name out of bounds.
name[99] = line;
As done previously, use strcpy to copy strings.
Note that, if found and if there is room in the buffer, fgets stores the newline character in the buffer, so
printf("%s, %s", name, line);
will very likely print staggered output, like
Alice
, 5551234567
A cursory refactoring:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char *remove_newline(char *string)
{
if (string)
string[strcspn(string, "\n")] = '\0';
return string;
}
int main(int argc, char **argv)
{
if (argc < 2) {
fprintf(stderr, "usage: %s t9_sequence\n", argv[0]);
return EXIT_FAILURE;
}
int size = strlen(argv[1]);
char letters[size][5];
int total_combinations = 1;
int current_combination[size];
for (int i = 0; argv[1][i]; i++) {
switch (argv[1][i]) {
default:
fprintf(stderr, "Invalid input: \"%c\"\n", argv[1][i]);
return EXIT_FAILURE;
case '0':
strcpy(letters[i], "+");
break;
case '2':
strcpy(letters[i], "abc");
break;
case '3':
strcpy(letters[i], "def");
break;
case '4':
strcpy(letters[i], "ghi");
break;
case '5':
strcpy(letters[i], "jkl");
break;
case '6':
strcpy(letters[i], "mno");
break;
case '7':
strcpy(letters[i], "pqrs");
break;
case '8':
strcpy(letters[i], "tuv");
break;
case '9':
strcpy(letters[i], "wxyz");
break;
}
total_combinations *= strlen(letters[i]);
}
memset(current_combination, 0, sizeof current_combination);
char combinations[total_combinations][size + 1];
for (int k = 0; k < total_combinations; k++) {
for (int set_idx = 0; set_idx < size; set_idx++) {
int letter_idx = current_combination[set_idx];
combinations[k][set_idx] = letters[set_idx][letter_idx];
}
combinations[k][size] = '\0';
for (int i = size - 1; i >= 0; i--) {
current_combination[i]++;
if (current_combination[i] != strlen(letters[i]))
break;
current_combination[i] = 0;
}
}
char name[128];
char number[128];
while (1) {
if (!fgets(name, sizeof name, stdin))
break;
if (!fgets(number, sizeof number, stdin))
break;
int found = 0;
for (int i = 0; i < total_combinations; i++) {
if (strstr(name, combinations[i])) {
found = 1;
break;
}
}
if (found || strstr(number, argv[1]))
printf("%s, %s\n", remove_newline(name), remove_newline(number));
}
}