Minh Tong Quat

#include <iostream>

using namespace std;

int max1, max2, max3, target;

int gcd(int x, int y) {
      if (x % y == 0) return y;
      return gcd(y, x % y);
}

void pour(int &x, int &y, int maxY) {
      // Pour from x to y
      int remain = maxY - y;
      if (remain > 0) {
            if (x < remain) {
                  y += x; x = 0;
            } else {
                  x -= remain; y = maxY;
            }
      }
}


void solve(int cup1, int cup2, int cup3, int target) {
      int divisor = gcd(max1, gcd(max2, max3));
      if (target % divisor != 0) {
            cout << endl << "Unable to pour";
            return;
      }

      if (cup1 == target || cup2 == target || cup3 == target) {
            cout << endl << "Done";
            return;
      }

      if (cup1 == 0) {
            pour(cup3, cup1, max1);
            cout << endl << "C -> A";
      } else if (cup2 == 0) {
            pour(cup1, cup2, max2);
            cout << endl << "A -> B";
      } else if (cup3 == 0) {
            pour(cup2, cup3, max3);
            cout << endl << "B -> C";
      } else if (cup2 == max2) {
            pour(cup2, cup3, max3);
            cout << endl << "B -> C";
      } else if (cup3 == max3) {
            pour(cup3, cup1, max1);
            cout << endl << "C -> A";
      } else {
            pour(cup2, cup3, max3);
            cout << endl << "B -> C";
      }

      solve(cup1, cup2, cup3, target);
}

int main()
{

      cout << endl << "Pouring Water";
      cout << endl;
      cout << endl << "Cup 1 has the most water.";
      cout << endl << "Cup 1 (A) = "; cin >> max1;
      cout << endl << "Cup 2 (B) = "; cin >> max2;
      cout << endl << "Cup 3 (C) = "; cin >> max3;
      cout << endl << "Target = "; cin >> target;
      cout << endl << "Cup 1 is full and Cup 2, 3 is empty";

      solve(max1, 0, 0, target);

      return 0;
}