Learn how to find the greatest common divisor in C language

To learn how to find the greatest common divisor in C language, you need specific code examples

The Greatest Common Divisor (GCD for short) refers to two or more integers The largest positive integer that can divide them. The greatest common denominator is often used in computer programming, especially when dealing with fractions, simplifying fractions, and solving problems such as the simplest ratio of integers. This article will introduce how to use C language to find the greatest common divisor and give specific code examples.

There are many ways to solve the greatest common divisor, such as the Euclidean algorithm and the GCD algorithm. Here we will use Euclidean's algorithm to demonstrate how to find the greatest common divisor.

Euclidean algorithm works by repeatedly dividing the larger of two numbers by the smaller number, and then dividing the remainder by the divisor until the remainder is 0. The final divisor is the greatest common divisor. The following is a code example for finding the greatest common divisor in C language:

#include <stdio.h>

int gcd(int a, int b) {
    if (b == 0) {
        return a;
    }
    return gcd(b, a % b);
}

int main() {
    int num1, num2;
    printf("请输入两个整数：");
    scanf("%d %d", &num1, &num2);
    int result = gcd(num1, num2);
    printf("最大公约数为：%d
", result);
    return 0;
}

In this code, we define a function gcd, which accepts two integers as parameters. In the function, we first determine whether b is equal to 0. If so, return a as the greatest common divisor. Otherwise, we call ourselves and take b and a % b as parameters to solve recursively to find the greatest common divisor. Finally, in the main function, we accept two integers entered by the user and pass them as parameters to the gcd function, and then print out the greatest common divisor.

Let’s simulate the execution process of this code, assuming that the two integers entered by the user are 10 and 25. First, we pass 10 as a and 25 as b to the gcd function. Since b is not 0, we need to call the gcd function again and pass 25 as a and 10 % 25 (i.e. 10) as b Go in. Now, we call the gcd function again and pass in 10 as a and 25 % 10 (which is 5) as b. At this time, b is still not 0, we call the gcd function again, and use 5 as a, 10 % 5 (i.e. 0) as b Pass it in. Since b is 0 at this time, the function will directly return a, which is 5. Therefore, the greatest common divisor is 5.

Euclidean algorithm is a very efficient method for solving the greatest common divisor. No matter how big the input integer is, the result can be obtained after a limited number of steps. I hope the code examples in this article can help you better understand the process of finding the greatest common divisor. If you are also interested in other knowledge of C language, you can continue to study in depth and continuously improve your programming abilities.

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