[面试] 水杯题实现

水杯题的代码实现：两个水杯a, b. 倒出c升水

#include <iostream>
using namespace std;

int gcd(int a, int b)
{
    if (b == 0)
        return a;
    else
        return gcd(b, a % b);
}

void solve(int a, int b, int curA, int curB, int c)
{
    if (curA == c)
        return;
    if (curB == c)
        return;
    if (curA + curB == c)
        return;

    if (curA == 0)
    {
        cout << "full(A) " << "a:" << curA << " b:" << curB << endl;
        return solve(a, b, a, curB, c);
    }
    else if (curB == b)
    {
        cout << "empty(B) " << "a:" << curA << " b:" << curB << endl;
        return solve(a, b, curA, 0, c);
    }
    else
    {
        int emptyB = b - curB;
        if (curA >= emptyB)
        {
            curB = b;
            curA -= emptyB;
        }
        else
        {
            curB += curA;
            curA = 0;
        }

        cout << "A->B " << "a:" << curA << " b:" << curB << endl;
        return solve(a, b, curA, curB, c);
    }
}

int main()
{
    int a, b, c;

    while(cin >> a >> b >> c)
    {
        if (a + b == c)
            cout << "full(a), full(b) " << "a:" << a << " b:" << b << endl;
        else if (a + b < c)
            cout << "No ans!" << endl;
        else
        {
            int d = gcd(a, b);
            if (c % d == 0)
            {
                if (a < b)
                {
                    int t = a;
                    a = b;
                    b = t;
                }
                solve(a, b, 0, 0, c);
            }
            else
                cout << "No ans!" << endl;
        }
    }
}