I want to create a C file which, via a binary-search-tree, reads from a text file, takes its identifiers (eg.include, stdio, hello, etc.), sorts them alphabetically, and returns what line number they appear on.
Desired terminal output:
Identifier: Hello
Counter: 2
Lines Appeared: [4, 6]
Issues:
test.txt
#include <stdio.h>
main() {
printf("Hello world!\n");
printf("Lochlann\n");
printf("Hello world!\n");
}
quetion.c
#include <stdio.h>
#include <ctype.h>
struct Node {
char * data;
int lineList[100];
int counter;
struct Word * word;
struct Node * ltree;
struct Node * rtree;
};
struct Node * head;
struct Node * newTree(char * identifier) {
struct Node * n = malloc(sizeof(struct Node));
n -> data = malloc(strlen(identifier) + 1);
n -> lineList = {};
n -> counter = 1;
strcpy(n -> data, identifier);
n -> ltree = n -> rtree = NULL;
return n;
}
struct Node * insert(struct Node * tree, char * identifier, int lineNumber) {
if (tree == NULL)
return newTree(identifier);
int cmp = strcmp(identifier, tree -> data);
if (cmp == 0) {
tree -> counter++;
tree -> lineList[tree -> counter - 1] = lineNumber;
return tree;
}
if (cmp < 0)
tree -> ltree = insert(tree -> ltree, identifier, lineNumber);
else
tree -> rtree = insert(tree -> rtree, identifier, lineNumber);
return tree;
}
void inorder(struct Node * tree) {
if (tree == NULL)
return;
inorder(tree -> ltree);
printf("Identifier: %s\nCounter: %i\nLines Appeared: ", tree -> data, tree -> counter);
for (int i = 0; i < tree -> counter; i++) {
printf("%d", tree -> lineList[i]);
//tree -> lineList[i] = lineNumber;
}
printf("\n");
inorder(tree -> rtree);
}
main() {
FILE * fp;
fp = fopen("test.txt", "r");
char buf[200];
char id[100];
int lineNumber = 1; //the tree->lineList should be [1,1,1,1,1,1]
int j;
while (fgets(buf, 100, fp)) {
int i = 0;
int len = strlen(buf);
for (j = 0, i = 0; i < len; i++) {
if (isalpha(buf[i]) || buf[i] == '_') {
while (buf[i] && (isalnum(buf[i]) || buf[i] == '_'))
id[j++] = buf[i++];
// have id
id[j] = 0;
//third argument adding line to linelist
head = insert(head, id, lineNumber);
j = 0;
}
}
}
inorder(head);
}
With little else on the go, here's a "mark-up" of your code. Please consider some / most / all of these comments for this program and for others.
#include <stdio.h>
#include <ctype.h>
struct Node {
char * data; // "generic" name. "token" might be better.
int lineList[100]; // limited, but okay for now
int counter;
// struct Word * word; // unused. keep things clean.
struct Node * ltree;
struct Node * rtree;
};
struct Node * head; // global variables are not recommended
struct Node * newTree(char * identifier, int lnNum ) {
// struct Node * n = malloc(sizeof(struct Node));
struct Node * n = calloc( 1, sizeof *n ); // use calloc
/* omitting test for NULL */
n -> data = malloc(strlen(identifier) + 1);
/* omitting test for NULL */
strcpy(n -> data, identifier); // do this here
// n -> lineList = {}; // unnecessary with calloc
n->lineList[ n->counter++ ] = lnNum; // missing!!!
// with calloc(), counter starts at zero
// strcpy(n -> data, identifier); // shifted to where used
// n -> ltree = n -> rtree = NULL; // unnecessary with calloc
return n;
}
struct Node * insert(struct Node * tree, char * identifier, int lineNumber) {
if (tree == NULL)
return newTree(identifier, lineNumber ); // missing param linenumber!
int cmp = strcmp(identifier, tree -> data);
if (cmp == 0) {
// tree -> counter++;
// tree -> lineList[tree -> counter - 1] = lineNumber;
/* omitting test for overrun */
tree -> lineList[ tree->counter ] = lineNumber;
tree->counter++;
return tree;
}
if (cmp < 0)
tree -> ltree = insert(tree -> ltree, identifier, lineNumber);
else
tree -> rtree = insert(tree -> rtree, identifier, lineNumber);
return tree;
}
void inorder(struct Node * tree) {
if (tree == NULL)
return;
inorder(tree -> ltree);
printf("Identifier: %s\nCounter: %i\nLines Appeared: ", tree -> data, tree -> counter);
for (int i = 0; i < tree -> counter; i++) {
printf("%d", tree -> lineList[i]);
//tree -> lineList[i] = lineNumber;
}
printf("\n");
inorder(tree -> rtree);
}
int main() { // proper declaration of 'main()'
FILE *fp = fopen("test.txt", "r"); // fewer lines
/* omitting test for success */
char buf[200];
// char id[100]; // not needed yet
int lineNumber = 0; // got zero lines so far
// int j; // willy-nilly variables
while (fgets(buf, sizeof buf, fp)) { // compiler knows dimensions
lineNumber++; // missing!
int len = strlen(buf);
for (int i = 0; i < len; /* i++ */) { // let body decide
if (isalpha(buf[i]) || buf[i] == '_') {
int j = 0; // NOW we need 'j' and..
char id[100];
while (buf[i] && (isalnum(buf[i]) || buf[i] == '_'))
id[j++] = buf[i++]; // here, 'i' is left on next character
// have id
id[j] = '\0'; // same, but conventional
//third argument adding line to linelist
head = insert(head, id, lineNumber);
// j = 0; // don't care about j anymore
}
else i++;
}
}
inorder(head);
return 0; // optional with newer compilers
}
You could even consider 'ditching' the copying of tokens from one buffer to another. Here's a slightly tighter for() loop for main():
for( int i = 0; buf[ i ]; i++ )
if (isalpha(buf[i]) || buf[i] == '_') {
int tokStart = i;
while (buf[i] && (isalnum(buf[i]) || buf[i] == '_'))
i++; // find end of token (or line)
char c = buf[i]; // remember this character
buf[i] = '\0'; // clobber it
head = insert(head, buf + tokStart, lineNumber);
buf[i--] = c; // restore character AND decrement
}