Question

i want to take a very long integer(it may contain upto 1000 digits). and i want to store it in an array so that each digit will sit in each place of the array.but if i try to use the code below it takes the whole number in the 0 position untill i press enter. but i can’t press enter. each digit will be scanned separately even though the user will write it as a complete number.

for(count=0;number[count]!='\0';count++){
            scanf("%d",number+count);
        }

what is the way there??

Answer 1

Don’t use scanf. Use fgets to get a line of input as a char*, then you can pull individual digits out of the char* as characters, and convert them to int digits yourself. scanf("%d", ...) will cause problems if the user enters input that can’t be parsed as a digit.

char *inputLine = malloc(sizeof(char) * (MAX_DIGITS + 1);
fgets(inputLine, MAX_DIGITS, stdin); // or replace stdin with a FILE *

fgets will consume the entire line of input up to the newline, or stop at the number of characters specified by argument 2.

If you want to continue reading digit-by-digit, then use getchar() to read individual characters, or fgetc(FILE *) to read individual characters from a file.

char *inputLine = malloc(sizof(char) * (MAX_DIGITS + 1));
char ch = getchar();
int i = 0;
while ((ch != '\n') && (ch != EOF) && (i < MAX_DIGITS))
{
    inputLine[i++] = ch;
    ch = getchar();
}