GCD&LCM计算

//
//  main.c
//  毛遵杰 18098531-i011-0019 D1 作业
//
//  Created by 毛遵杰 on 2018/11/19.
//  Copyright © 2018 毛遵杰. All rights reserved.
//

#include <stdio.h>
//保存到数组中，并返回数组长度。
int saveFactor(int factors[],int number)

{
 
    int factorsLength = 0, i = 0;
    for (i = 1; i < number + 1; ++i)
    {
        if (number % i == 0)
        {
            factors[factorsLength] = i;
            ++factorsLength;
        }
    }
    return factorsLength;
}

//打印约数（print factors)

void printFactors(int factors[], int length)
{
    
    for (int i = 0; i < length; i++)
    {
        printf("%d ", factors[i]);
    }
    printf("\n");
}

//打印素数 (print prime)
void printPrime(int factors[], int length)
{
    int i, j;
    for (i = 1; i < length; ++i)
    {
        int a = 0;
        for (j = 2; j < factors[i]; ++j)
        {
            if (factors[i] % j == 0)
            {
                a++;
            }
        }
        if (a == 0)
        {
            printf("%d ", factors[i]);
        }
    }
    printf("\n");
}

int main()
{
    int firstNumber, secondNumber, i, j, firstFactorLength, secondFactorLength;
    int firstFactors[100], secondFactors[100];
    
    printf("Please provide 2 integer number\n");
    
    int output = scanf("%d %d", &firstNumber, &secondNumber);
    
    // if the provide number is illegal,return
    if (output == 0)
    {
        printf("Byebye\n");
        return 0;
    }
    
    //save firstNumber's factors into the array
    firstFactorLength = saveFactor(firstFactors, firstNumber);
    secondFactorLength = saveFactor(secondFactors, secondNumber);
    
    printf("First number's fators:\n");
    printFactors(firstFactors, firstFactorLength);
    
    printf("Second number's fators:\n");
    printFactors(secondFactors, secondFactorLength);
    
    printf("first number's prime fators:\n");
    printPrime(firstFactors, firstFactorLength);
    
    printf("Second number's prime fators:\n");
    printPrime(secondFactors, secondFactorLength);
    
    // print gcd
    int gcd = 0;
    for (i = 0; i < firstFactorLength; i++)
    {
        for (j = 0; j < secondFactorLength; j++)
        {
            if (firstFactors[i] == secondFactors[j])
            {
                gcd = firstFactors[i];
                break;
            }
        }
    }
    printf("gcd = %d\n", gcd);
    
    //print lcm
    int lcm = firstNumber * secondNumber / gcd;
    printf("LCM = %d\n", lcm);
    
    return 0;
}