整数变换问题

标签：算法   笔试   

No Solution

#include "stdafx.h"
#include<vector>
#include<iostream>

using namespace std;
typedef unsigned char byte;
struct  Node
{
	vector<byte>path;
	int current_value;
};
Node solution;
vector<Node>nextnodelist;
bool integer_trans(int m, int n, vector<Node>nodelist)
{
	if (nodelist[0].path.size() == 25)
	{
		cout << "已达到最大层数，未找到" << endl;
		return true;
	}
	nextnodelist.clear();
	cout << nextnodelist.size() << endl;
	int k = 0;
	while (k < nodelist.size())
	{
		if (nodelist[k].current_value % 3 == 0)
		{
			Node node;
			node.path = nodelist[k].path;
			node.path.push_back(0);
			node.current_value = nodelist[k].current_value / 3;
			nextnodelist.push_back(node);
			if (node.current_value == n)
			{
				solution = node;
				return true;
			}
		}

		Node node1;
		node1.path = nodelist[k].path;
		node1.path.push_back(1);
		node1.current_value = nodelist[k].current_value * 2;
		nextnodelist.push_back(node1);
		if (node1.current_value == n)
		{
			solution = node1;
			return true;
		}

		Node node2;
		node2.path = nodelist[k].path;
		node2.path.push_back(2);
		node2.current_value = nodelist[k].current_value * 2+1;
		nextnodelist.push_back(node2);
		if (node2.current_value == n)
		{
			solution = node2;
			return true;
		}

		k++;
	}

	return false;

}


void solve(int m, int n)
{
	Node nn;
	nn.current_value = m;
	nextnodelist.push_back(nn);
	bool flag = false;
	while (!flag)
	{
		vector<Node>nodelist(nextnodelist);
		flag = integer_trans(m, n, nodelist);
	}
}



int _tmain(int argc, _TCHAR* argv[])
{
	solve(4, 15);

	system("pause");
	return 0;
}

每个node存储它之前操作的记录，0代表f，即/3，1代表*2,2代表*2+1，value存储当前值。nodelist只存储一层的节点即可。

因为每次对f先进行操作，也先进行存储，所以找到的第一个满足要求的解也是字典序最小的，直接返回即可。

整数变换问题

标签：算法   笔试   

原文地址：http://blog.csdn.net/u014568921/article/details/46941463