Creating array to hold 1000000 numbers - c

Question

I wrote a code in C that read a text file with numbers into memory and the create an 2d int array to store them.
The file has the following format:
9
9 5 6 2235 45558 6 5544 56565 2
The first number is the size of the array and the second line holds as many numbers as the first line says.
MY problem is that the size of the array can't hold more than ~30.000 numbers. How can I make the following code so I can make the array hold until 1.000.000 numbers? I know that I should use some king of long integer but I couldn't do it.
Heres the code
#include <stdio.h>
#include <stdlib.h>
int is_end(char* input) {
return *input == 0;
}
int is_separator(char* input) {
return *input == '\n' || *input == ' ';
}
char* eat_separators(char* input) {
while (is_separator(input))
++input;
return input;
}
size_t count_lines(char* input) {
size_t rows = 1;
while (!is_end(input)) {
if (is_separator(input)) {
++rows;
input = eat_separators(input);
}
else {
++input;
}
}
return rows;
}
char** get_lines(char* input, size_t number_of_rows) {
char* from = input;
size_t length = 0;
size_t line = 0;
size_t i;
char** lines = (char**)malloc(number_of_rows * sizeof(char*));
do {
if (is_end(input) || is_separator(input)) {
lines[line] = (char*)malloc(length + 1);
for (i = 0; i < length; ++i)
lines[line][i] = *(from + i);
lines[line][length] = 0;
length = 0;
++line;
input = eat_separators(input);
from = input;
}
else {
++length;
++input;
}
} while (!is_end(input));
/*
lines[line] = (char*)malloc(length + 1);
for (i = 0; i < length; ++i)
lines[line][i] = *(from + i);
lines[line][length] = 0;
++line; */
return lines;
}
int main(int argc, char* argv[]) {
char** lines;
size_t size;
size_t number_of_rows;
int count;
int* children;
FILE *input, *output;
char *contents;
int fileSize = 0;
int i;
input = fopen("xxx.in", "r");
long int filepos = 0L;
fseek(input, 0L, SEEK_END);
fileSize = ftell(input);
fseek(input, 0L, SEEK_SET);
contents = (char*)malloc(fileSize + 1);
size = fread(contents, 1, fileSize, input);
contents[size] = 0;
fclose(input);
number_of_rows = count_lines(contents);
lines = get_lines(contents, number_of_rows);
if ((count = atoi(lines[0])) <= 0 || count > 1000000){
return 1;
}
children = (int*)malloc(count * sizeof(int));
for (i = 0; i < count; ++i) {
if ((children[i] = atoi(lines[i + 1])) <= 0 )
return(-1);
}
// a check to see if everything stored in the array
for(i = 0;i<count;i++)
{
printf(" %d : %d\n", i, children[i]);
}
free(children);
free(lines);
// This is the end! Oh my dear friend, the end!
return 0;
}

Answer 1

First Let me explaint the reason of having only 30.000 number that will give reply to your question?
Basically you are trying to convert the character to ASCII values. Let us take the example of character x whos ASCII value is 120. You are changing the character x with 120, the storage capacity of x is 1 byte but the storage capacity of 120 is 3 bytes. So, basically you have to do memory allocation of 3 times higher the actual value computed as 1 byte is expanding into 3 bytes.
In Your code increase the memory allocation 3 times then your problem would be solved.