C program for modular division of large number

1. C code for modular division of big numbers:

2. How to get modular division of two very large numbers larger or beyond than long int in c programming language

#define MAX 10000

int validate(char []);
int modulerDivision(char[],unsigned long);

int main(){

    char dividend[MAX];
    unsigned long int divisor,remainder;

    printf("Enter dividend: ");
         return 0;

    printf("Enter divisor: ");

    remainder = modulerDivision(dividend,divisor);

    printf("Modular division: %s %% %lu  =  %lu",dividend,divisor,remainder);

    return 0;

int validate(char num[]){
    int i=0;

         if(num[i] < 48 || num[i]> 57){
             printf("Invalid positive integer: %s",num);
             return 1;

    return 0;

int modulerDivision(char dividend[],unsigned long divisor){
    unsigned long temp=0;
    int i=0;

         temp = temp*10 + (dividend[i] -48);
             temp = temp % divisor;

    return temp;

Sample output:
Enter dividend: 123456789
Enter divisor: 56
Modular division: 123456789 % 56 = 29

Algorithm to find the modular division of large numbers:

Use array to store big numbers. 


Unknown said...

Hi, I need help for my assignment, I need to modular addition and modular multiplication on large integers ie 128 using arrays. My numbers are stored in char arrays in decimal form, so how to perform modular addition and multiplication on large char arrays. please

Lemza said...

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