C Exercises: Divide two integers without multiply, divide, modulating

Last update on December 20 2024 13:07:32 (UTC/GMT +8 hours)

Write a C program to divide two given integers without using the multiplication, division and mod operator. Return the quotient after dividing.

C Code:

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>

int divide_two(int dividend_num, int divisor_num)
{
    int sign = (float) dividend_num / divisor_num > 0 ? 1 : -1;
    unsigned int dvd = dividend_num > 0 ? dividend_num : -dividend_num;
    unsigned int dvs = divisor_num > 0 ? divisor_num : -divisor_num;
    unsigned int bit_num[33];
    unsigned int i = 0;
    long long d = dvs;

    bit_num[i] = d;
    while (d <= dvd) {
        bit_num[++i] = d = d << 1;
    }
    i--;

    unsigned int result = 0;
    while (dvd >= dvs) {
        if (dvd >= bit_num[i]) {
            dvd -= bit_num[i];
            result += (1<<i);
        } else {
            i--;
        }
    }

    if (result > INT_MAX && sign > 0) {
        return INT_MAX;
    }
    return (int) result * sign;
}

int main(void)
{
    int dividend_num = 15;
	int divisor_num = 3;
	printf("Quotient after dividing %d and %d : %d", dividend_num, divisor_num, divide_two(dividend_num, divisor_num));
    return 0;
}

Sample Output:

Quotient after dividing 15 and 3 : 5

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