最大公因数、最小公倍数相关

gcd_lcm.c

int gcd(int a, int b){
    int rmd;  // remainder
    if(a<b)    // insure a>b
        return gcd(b,a);
    while((rmd=a%b)!=0){
        a = b;
        b = rmd;
    }   // loop down, b is the gcd
    return b;
}

int lcm(int a, int b){
    return a*b/gcd(a,b);
}

int multiGcd(int size, int *arr){
    int mg = arr[0];
    for(int i=1;i<size;i++)
        mg = gcd(mg, arr[i]);
    return mg;
}

int multiLcm(int size, int *arr){
    int ml = arr[0];
    for(int i=1;i<size;i++)
        ml = lcm(ml, arr[i]);
    return ml;
}