text: i want c program in c language lcd gcd with recursive function?   to calculate the gcd of two numbers recursively, you can use  1) euclid's algorithm:   int gcd(int m, int n) {    if ((m % n) == 0)       return n;    else       return gcd(n, m % n); } or 2) dijkstra's algorithm int gcd(int m, int n) {    if(m == n)       return m;    else if (m > n)       return gcd(m-n, n);    else       return gcd(m, n-m); }   or 3) brute force guessing int trydivisor(int m, int n, int g) {    if (((m % g) == 0) && ((n % g) == 0))       return g;    else       return trydivisor(m, n, g - 1); } in this last one, g is a guess. if the guess works, then it returns the guess. otherwise, it tries a smaller guess.