using sscanf(), read string to array of int? - algorithm

Question

i have this string:
12 4 the quick 99 -1 fox dog \
what i want in my program:
myArray[] = {12, 4, 99, -1};
how i do a multiple number scanning?

Answer 1

See my answer to your other question here. It's a relatively simple matter to replace the strtok section to recognize non-numeric words and neither increment the count (in the first pass) nor load them into the array (in the second pass).
The code has changed as follows:
Using an input file of:
12 3 45 6 7 8
3 5 6 7
7 0 -1 4 5
12 4 the quick 99 -1 fox dog \
it produces output along the lines of:
0x8e42170, size = 6:
12 3 45 6 7 8
0x8e421d0, size = 4:
3 5 6 7
0x8e421e0, size = 5:
7 0 -1 4 5
0x8e42278, size = 4:
12 4 99 -1
Here's the code that produced that output:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
// This is the linked list of integer arrays.
typedef struct _tIntArray {
int size;
int *array;
struct _tIntArray *next;
} tIntArray;
static tIntArray *first = NULL;
static tIntArray *last = NULL;
// Check that argument is numeric, optional minus sign followed by
// zero or more digits (you may want one or more).
static int isAllNumeric (char *word) {
char *s = word;
if (*s == '-')
s++;
for (; *s != '\0'; s++)
if ((*s < '0') || (*s > '9'))
return 0;
return 1;
}
// Add a line of integers as a node.
static int addNode (char *str) {
tIntArray *curr; // pointers for new integer array.
char *word; // word within string.
char *tmpStr; // temp copy of buffer.
int fldCnt; // field count for line.
int i;
// Count number of fields.
if ((tmpStr = strdup (str)) == NULL) {
printf ("Cannot allocate duplicate string (%d).\n", errno);
return 1;
}
fldCnt = 0;
for (word = strtok (tmpStr, " "); word; word = strtok (NULL, " "))
if (isAllNumeric (word))
fldCnt++;
free (tmpStr);
// Create new linked list node.
if ((curr = malloc (sizeof (tIntArray))) == NULL) {
printf ("Cannot allocate integer array node (%d).\n", errno);
return 1;
}
curr->size = fldCnt;
if ((curr->array = malloc (fldCnt * sizeof (int))) == NULL) {
printf ("Cannot allocate integer array (%d).\n", errno);
free (curr);
return 1;
}
curr->next = NULL;
for (i = 0, word = strtok (str, " "); word; word = strtok (NULL, " "))
if (isAllNumeric (word))
curr->array[i++] = atoi (word);
if (last == NULL)
first = last = curr;
else {
last->next = curr;
last = curr;
}
return 0;
}
int main(void) {
int lineSz; // current line size.
char *buff; // buffer to hold line.
FILE *fin; // input file handle.
long offset; // offset for re-allocating line buffer.
tIntArray *curr; // pointers for new integer array.
int i;
// Open file.
if ((fin = fopen ("qq.in", "r")) == NULL) {
printf ("Cannot open qq.in, errno = %d\n", errno);
return 1;
}
// Allocate initial line.
lineSz = 2;
if ((buff = malloc (lineSz+1)) == NULL) {
printf ("Cannot allocate initial memory, errno = %d.\n", errno);
return 1;
}
// Loop forever.
while (1) {
// Save offset in case we need to re-read.
offset = ftell (fin);
// Get line, exit if end of file.
if (fgets (buff, lineSz, fin) == NULL)
break;
// If no newline, assume buffer wasn't big enough.
if (buff[strlen(buff)-1] != '\n') {
// Get bigger buffer and seek back to line start and retry.
free (buff);
lineSz += 3;
if ((buff = malloc (lineSz+1)) == NULL) {
printf ("Cannot allocate extra memory, errno = %d.\n", errno);
return 1;
}
if (fseek (fin, offset, SEEK_SET) != 0) {
printf ("Cannot seek, errno = %d.\n", errno);
return 1;
}
continue;
}
// Remove newline and process.
buff[strlen(buff)-1] = '\0';
if (addNode (buff) != 0)
return 1;
}
// Dump table for debugging.
for (curr = first; curr != NULL; curr = curr->next) {
printf ("%p, size = %d:\n ", curr, curr->size);
for (i = 0; i < curr->size; i++)
printf (" %d", curr->array[i]);
printf ("\n");
}
// Free resources and exit.
free (buff);
fclose (fin);
return 0;
}