KwCheng's blog

http://formatmysourcecode.blogspot.tw/

int hcf(int a , int h)
{
        int temp;
        while(1)
        {
                temp = a % h;
                if(temp == 0)
                {
                        return h;
                }
                a = h;
                h = temp;
        }
}

int relativePrimes(int* num , int n)
{
        int count = 0;
        for(int i = 0 ; i < n ; i++)
        {
                for(int j = i + 1 ; j < n ; j++)
                {
                     int a = *(num + i);
                     int b = *(num + j);
                     int gcd = hcf(a , b);
                     if(gcd == 1)
                     {
                        count++;
                     }   
                }
        }
        return count;
}

int hcf(int a , int h)
{
        int temp;
        while(1)
        {
                temp = a % h;
                if(temp == 0)
                {
                        return h;
                }
                a = h;
                h = temp;
        }
}

int combination_pascal(int n , int r)
{
        if(r == 0 || n == r)
        {
                return 1;
        }
        return combination_pascal(n - 1 , r) + combination_pascal(n - 1 , r - 1); 
}

int factor(int n)
{
        int ret = 1;
        for(int i = 2 ; i <= n ; i++ )
        {
                ret = ret * i;
        }
        return ret;
}

int combination(int n , int r)
{
        int ret = factor(n) / (factor(r) * factor(n-r));
        return ret;
}

int* numArray(int n)
{
        int* num = (int*)malloc(n * sizeof(int));
        
        for(int i = 0 ; i < n ; i++)
        {
                scanf("%d\n" , num + i);
        }

        return num;
}

int factor(int n)
{
        int ret = 1;
        for(int i = 2 ; i <= n ; i++ )
        {
                ret = ret * i;
        }
        return ret;
}