5 升 3 升 容器，產生任何數量的水的演算法實現

You have a five-quart jug, a three-quart jug, and an unlimited supply of water (but no measuring cups). How would you come up with exactly
four quarts of water? Note that the jugs are oddly shaped, such that filling up exactly "half" of the jug would be impossible.

演算法不夠最佳化，可以實現產生任何容量的水。 但是如果輸入的水容量過大，會導致計算時間過程。

日後有時間，在考慮其他的實現，以及最佳化。放在這裡，只是作為一個記錄。

#include <iostream>#include <stack>using namespace std;#define JUG_A   5#define JUG_B   3struct node{        struct node * parent;        struct node * childs;        struct node * next;        int a;  /* jug a */        int b;  /* jug b */        int c; /* total of summary */        node (node* pNode)        {                a = pNode->a;                b = pNode->b;                c = pNode->c;                parent = pNode;                childs = NULL;                next = NULL;        }        node ()        {                parent = NULL;                childs = NULL;                next = NULL;                a = 0;                b = 0;                c = 0;        }        bool OK(int n) {                if(a == n || b == n || c == n                /*|| a+b == n || a + c == n || b + c == n*/)                {                        return true;                }                return false;        }};void printNode(const node * pNode){        cout << " " << pNode->a << " " << pNode->b << " " << pNode->c << endl;}node *fillNode(node* pNode ){        int t;        node * tmp;        /* fill up jug a */        node* pFillJugA  = new node(pNode);        pNode->childs = pFillJugA;        tmp = pFillJugA;        pFillJugA->a = JUG_A ;        /* fill up jug b */        node * pFillJugB = new node(pNode);        tmp->next = pFillJugB;        tmp = pFillJugB;        pFillJugB->b = JUG_B;        if(pNode->a > 0)        {                /* from jug a to b */                node *pFromAToB = new node(pNode);                tmp->next = pFromAToB ;                tmp = pFromAToB;                t = JUG_B - pFromAToB->b;                pFromAToB->a -= t;                pFromAToB->b += t;        }        if(pNode->b > 0)        {                /* from jug b to a */                node * pFromB2A = new node(pNode);                tmp->next = pFromB2A;                tmp = pFromB2A;                t = JUG_A - pFromB2A->a ;                t = t > pFromB2A->b ? pFromB2A->b : t;                pFromB2A->a += t;                pFromB2A->b -= t;        }        if(pNode->a > 0)        {                /* from a to c */                node * pFromA2C = new node(pNode);                tmp->next = pFromA2C;                tmp = pFromA2C;                pFromA2C->c += pFromA2C->a;                pFromA2C->a = 0;        }        if(pNode->b > 0)        {                /* from b to c */                node * pFromB2C = new node(pNode);                tmp->next = pFromB2C;                tmp = pFromB2C;                pFromB2C->c += pFromB2C->b;                pFromB2C->b = 0;        }        return pFillJugA;}void destroyNode(stack<node *> &sn){        node * first, *tmp;        while(!sn.empty())        {                first = sn.top();                sn.pop();                while(first)                {                        tmp = first->next;                        delete first;                        first = tmp;                }        }}void search(int n){        stack<node *> sNode;        node * cur =  new node();        sNode.push(cur);        bool flag = false;        node * first , * tmp;        do        {                first = NULL;                cur = sNode.top();                while(cur)                {                        if(cur->OK(n)) {flag =true; break;}                        node * retnode = fillNode(cur);                        if(first == NULL) { first = retnode;}                        else {                                tmp = first;                                while(tmp->next)                                {                                        tmp = tmp->next;                                }                                tmp->next = retnode;                        }                        cur = cur->next;                }                sNode.push(first);        } while(!flag);        stack<node*> outPutNode;        while(cur)        {                outPutNode.push(cur);                cur = cur->parent;        }        cout <<endl;        while(!outPutNode.empty())        {                printNode(outPutNode.top());                outPutNode.pop();        }        destroyNode(sNode);}int main(){        int n ;        cout << endl<< "Please input the quart you want to get : " ;        while(cin >> n)        {                if(n <= 0) { break;}                search(n);                cout << endl << "Please input the quart you want to get : " ;        }        return 0;}