C++ 执行函数时出现问题（递归）
该计划的目标是列举一个人通过地铁系统从a站到L站的所有可能路径，而无需多次越过轨道。我知道有640条可能的路径，正如指导老师告诉我们的，我们用邻接矩阵编写了这个程序，作为C语言的早期作业。现在的目标是做同样的事情，即枚举所有可能的路线，并打印出每条路线，除了使用类（特别是3类：SubwaySystem、Station和Track），而这次不使用矩阵。这是地铁系统本身的示意图 我和助教讨论了这个项目以及如何实施。他给了我一些想法，比如使用数组来表示车站和轨道，我决定使用我在文章底部的整个代码中展示的方法 让我向您展示我的代码中我无法解决的问题区域（递归对我来说是新的）C++ 执行函数时出现问题（递归）,c++,arrays,function,recursion,C++,Arrays,Function,Recursion,该计划的目标是列举一个人通过地铁系统从a站到L站的所有可能路径，而无需多次越过轨道。我知道有640条可能的路径，正如指导老师告诉我们的，我们用邻接矩阵编写了这个程序，作为C语言的早期作业。现在的目标是做同样的事情，即枚举所有可能的路线，并打印出每条路线，除了使用类（特别是3类：SubwaySystem、Station和Track），而这次不使用矩阵。这是地铁系统本身的示意图 我和助教讨论了这个项目以及如何实施。他给了我一些想法，比如使用数组来表示车站和轨道，我决定使用我在文章底部的整个代码中展
void SubwaySystem:：SearchRoute（int当前站点ID）
{
if（my_station[当前_station\u ID]。track_start\u ID==33）//查找到车站L的成功路线。
//该条件设置为检查33，因为轨道起始ID为33将对应于车站L。
{
count_routes++；//将1添加到变量“count_routes”
我想你的主要问题是：
my_track[Current_Station_ID].visited = 1; //mark this track as visited
my_track[Current_Station_ID].node_2 = 1; //mark its corresponding track as visited
cout << my_track[Current_Station_ID].node_1; //save this track
SearchRoute(Current_Station_ID++); <<<<<<<< PROBLEM
i--; //Backtrack this track <<<<<<< Also this will do nothing
my_track[Current_Station_ID].visited = 0; <<<<<<< Now Current_Station_ID is 1 more than you are expecting it to be.
my_track[Current_Station_ID].node_2 = 0;//mark its corresponding track as unvisited
这是一个有效的解决方案，它给出了605个解决方案，我认为这是正确的
// RandomTest.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;
class Track
{
public:
//Default Constructor
Track();
//Overload Constructor
Track(char, char, int station, int opposite);
//Destructor
~Track();
//Member variables
char node_1; // node_1 and node_2 represent stations (for example
char node_2; // node_1 would be station A and node_2 would be station B)
bool visited;
int connected_station;
int opposite_track;
};
class Station
{
public:
//Default Constructor
Station();
//Destructor
~Station();
//Overload Constructor
Station(char, int, int);
//Member variables
char station_name;
int track_starting_ID;
int track_size;
};
class SubwaySystem
{
public:
//Default Constructor
SubwaySystem();
//Destructor
~SubwaySystem();
//Recursive function
void SearchRoute(int);
//Other member functions
friend ostream& operator<<(ostream& os, const Track& my_track);
friend ostream& operator<<(ostream& os, const Station& my_station);
//Member variables
Track my_track[34];
Station my_station[12];
int count_routes;
int Current_Station_ID;
//String to save found route
void SearchRoute(int Current_Station_ID, int from_track_id, Track **currentPath, int pathCount);
};
// **cpp**
//#include "subway.h"
using namespace std;
Track::Track()
{
visited = 0;
}
Track::~Track()
{
}
Track::Track(char pass_track1, char pass_track2, int station, int opposite)
{
node_1 = pass_track1;
node_2 = pass_track2;
connected_station = station;
opposite_track = opposite;
visited = false;
}
Station::Station()
{
}
Station::~Station()
{
}
Station::Station(char pass_station_name, int pass_start, int pass_size)
{
station_name = pass_station_name;
track_starting_ID = pass_start;
track_size = pass_size;
}
SubwaySystem::SubwaySystem()
{
//Initialize tracks
//node_1, node_2
my_track[0] = Track('a', 'b', 1, 1);
my_track[1] = Track('b', 'a', 0, 0);
my_track[2] = Track('b', 'c', 2, 6);
my_track[3] = Track('b', 'd', 3, 8);
my_track[4] = Track('b', 'e', 4, 10);
my_track[5] = Track('b', 'f', 5, 15);
my_track[6] = Track('c', 'b', 1, 2);
my_track[7] = Track('c', 'e', 4, 11);
my_track[8] = Track('d', 'b', 1, 3);
my_track[9] = Track('d', 'e', 4, 12);
my_track[10] = Track('e', 'b', 1, 4);
my_track[11] = Track('e', 'c', 2, 7);
my_track[12] = Track('e', 'd', 3, 9);
my_track[13] = Track('e', 'g', 6, 17);
my_track[14] = Track('e', 'h', 7, 19);
my_track[15] = Track('f', 'b', 1, 5);
my_track[16] = Track('f', 'h', 7, 20);
my_track[17] = Track('g', 'e', 4, 13);
my_track[18] = Track('g', 'k', 10, 28);
my_track[19] = Track('h', 'e', 4, 14);
my_track[20] = Track('h', 'f', 5, 16);
my_track[21] = Track('h', 'i', 8, 24);
my_track[22] = Track('h', 'j', 9, 26);
my_track[23] = Track('h', 'k', 10, 29);
my_track[24] = Track('i', 'h', 7, 21);
my_track[25] = Track('i', 'k', 10, 30);
my_track[26] = Track('j', 'h', 7, 22);
my_track[27] = Track('j', 'k', 10, 30);
my_track[28] = Track('k', 'g', 6, 18);
my_track[29] = Track('k', 'h', 7, 23);
my_track[30] = Track('k', 'i', 8, 25);
my_track[31] = Track('k', 'j', 9, 27);
my_track[32] = Track('k', 'l', 11, 33);
my_track[33] = Track('l', 'k', 10, 32);
//Initialize stations
//station_name, track_starting_ID, track_size
my_station[0] = Station('a', 0, 1);
my_station[1] = Station('b', 1, 5);
my_station[2] = Station('c', 6, 2);
my_station[3] = Station('d', 8, 2);
my_station[4] = Station('e', 10, 5);
my_station[5] = Station('f', 15, 2);
my_station[6] = Station('g', 17, 2);
my_station[7] = Station('h', 19, 5);
my_station[8] = Station('i', 24, 2);
my_station[9] = Station('j', 26, 2);
my_station[10] = Station('k', 28, 5);
my_station[11] = Station('l', 33, 1);
//Initiaize other members
count_routes = 0;
Current_Station_ID = 0;
}
SubwaySystem::~SubwaySystem()
{
}
void SubwaySystem::SearchRoute(int Current_Station_ID, int from_track_id, Track **currentPath, int pathCount)
{
if(my_station[Current_Station_ID].track_starting_ID == 33)
{
count_routes++; //Add 1 into the variable “count_routes”
cout << count_routes << " ";
for(int i= 0; i < pathCount; i++)
{
cout << *currentPath[i];
}
cout << endl;
return;
}
else //Get into recursive Function Body
{
for(int i = my_station[Current_Station_ID].track_starting_ID; i < my_station[Current_Station_ID].track_starting_ID + my_station[Current_Station_ID].track_size; i++)
{
//check all the tracks that we have visited before
bool visited = false;
for(int n = 0; n < pathCount; n++)
{
if(currentPath[n] == &my_track[i] || i == currentPath[n]->opposite_track) visited = true;
}
if(!visited)
{
int nextStation = my_track[i].connected_station;
currentPath[pathCount] = &my_track[i];
SearchRoute(nextStation, i, currentPath, pathCount + 1);
}
}
}
}
ostream& operator<<(ostream& os, const Track& my_track)
{
os << my_track.node_1 << '.' << my_track.node_2;
return os;
}
ostream& operator<<(ostream& os, const Station& my_station)
{
os << my_station.station_name << '.' << my_station.track_starting_ID << '.' << my_station.track_size;
return os;
}
//This is where the above recursive function SearchRoute goes. I posted it separately so it's easier to read.
// **main**
//#include "subway.h"
int _tmain(int argc, _TCHAR* argv[])
{
Track *tempTracks[34];
SubwaySystem findPaths;
findPaths.SearchRoute(0, -1, tempTracks, 0);
getchar();
return 0;
}
//RandomTest.cpp：定义控制台应用程序的入口点。
//
#包括“stdafx.h”
#包括
#包括
使用名称空间std；
班级轨道
{
公众：
//默认构造函数
轨道（）；
//重载构造函数
轨道（char，char，int车站，int对面）；
//析构函数
~Track（）；
//成员变量
char node_1；//node_1和node_2表示站点（例如
char node_2；//节点_1将是站点A，节点_2将是站点B）
布尔访问；
国际联络站；
int对向轨道；
};
班级站
{
公众：
//默认构造函数
车站（）；
//析构函数
~Station（）；
//重载构造函数
车站（字符，整数，整数）；
//成员变量
字符站名称；
int track_starting_ID；
int轨道尺寸；
};
等级地铁系统
{
公众：
//默认构造函数
地铁系统（）；
//析构函数
~SubwaySystem（）；
//递归函数
无效搜索路径（int）；
//其他成员职能
friend ostream&operator我找到了640条路线：
#include <stdio.h>
const char *connectom[] = {
"B", // A
"ACDEF", // B
"BE", // C
"BE", // D
"CDBGH", // E
"BH", // F
"EK", // G
"EFJKI", // H
"HK", // I
"HK", // J
"HIJGL", // K
"K" // L
};
char tracks[0x100];
char strout[0x100];
void path(char x, char *s) {
*s++ = x;
if(x == 'L') {
*s = 0;
printf("path=%s\n", strout);
} else {
for(const char *p = connectom[x - 'A']; *p; p++) {
unsigned char track_ndx = x > *p? (x << 4) ^ *p : (*p << 4) ^ x;
if(tracks[track_ndx] == 0) {
tracks[track_ndx] = 1;
path(*p, s);
tracks[track_ndx] = 0;
} // if
} // for
} // else
} // path
int main(int argc, char **argv) {
path('A', strout);
} // main
#包括
常量字符*connectom[]={
“B”//A
“ACDEF”//B
“BE”//C
“BE”//D
“CDBGH”，//E
“BH”，//F
“EK”，//G
“EFJKI”，//H
“HK”//I
“HK”//J
“HIJGL”，//K
“K”//L
};
字符轨道[0x100]；
字符strout[0x100]；
无效路径（字符x，字符*s）{
*s++=x；
如果（x='L'）{
*s=0；
printf（“路径=%s\n”，strout）；
}否则{
for（const char*p=connectom[x-'A']；*p；p++）{
无符号字符磁道\u ndx=x>*p？（x缩短故事，精简到相关代码，并明确指出错误/问题。1分钟后，这个问题怎么会有2张赞成票？！阅读需要2分钟以上，理解也需要1小时！@MM我也是，再花30分钟理解数学/几何或其他任何东西，我很抱歉。我意识到这一点st非常长。但是我想发布所有我能发布的信息，以便让回答者更清楚（我知道这不是一个单词=）。如果有人可以编辑它，使其成为一个更合适的帖子。我将不胜感激。也感谢您对此进行了投票。这很快。只是一个风格说明。虽然您在声明函数时没有参数的名称，但您应该这样做，因为它使阅读代码的人更清楚这些参数的意图。好的。我认为i--将有助于回溯。问题是，当我尝试实现您的代码版本时，在第一种情况下，当仍然使用当前的_Station_ID时，程序会陷入无限循环。在第二种情况下，使用i时，程序会给出一个巨大的数字。还要确保您在if语句中也使用了i。if（my_track[i]。visted==0）第一种情况下的无限循环将是因为当if语句为false时，CurruntPosixIdID不会被更改。我将把它添加到应答器FROST OFF中，谢谢您试图帮助我。现在程序崩溃了。如果您有C++编译器，如果您在计算机上运行它，检查结果可能会更容易一些。（你不必担心，我愿意测试它）。另外，出于好奇，当我在for循环中递增时，递归调用中的I+1函数会发生什么变化。我注意到我的代码中存在另一个问题。我使用的是同一个计数器（Current_Station_ID）对于大小不同的my_station阵列和my_track阵列。也许您可以帮助我解决这个问题，除非这不重要。编辑：我会再试一次。好的，现在我得到的总路线计数为89，这意味着我们正在接近=）.我刚才只得到1。但它仍然不完全正确，因为总的可能路线是640。如果你确定它是640，那么请检查车站和轨道之间的所有链接是否正确。乔，你是有史以来最伟大的人。非常感谢你抽出时间来帮我。我正在尝试看看这是如何工作的现在。我对不断打扰你感到很抱歉，但你是我现在唯一可以求助的人。我有一个问题，为什么你的main中有一个函数getchar（）？它在任何地方都没有定义。而且我在尝试打印cout getchar（）时不断出错只是为了使控制台窗口不会关闭。您可以将其取出。不确定为什么使用指针会出现错误。尝试打印出对象的部分。例如：cout node_2；哇，很好。这就是
my_track[Current_Station_ID].visited = 1; //mark this track as visited
my_track[Current_Station_ID].node_2 = 1; //mark its corresponding track as visited
cout << my_track[Current_Station_ID].node_1; //save this track
SearchRoute(Current_Station_ID++); <<<<<<<< PROBLEM
i--; //Backtrack this track <<<<<<< Also this will do nothing
my_track[Current_Station_ID].visited = 0; <<<<<<< Now Current_Station_ID is 1 more than you are expecting it to be.
my_track[Current_Station_ID].node_2 = 0;//mark its corresponding track as unvisited
void SubwaySystem::SearchRoute(int Current_Station_ID, int from_track_id, Track *currentPath, int pathCount)
{
if(my_station[Current_Station_ID].track_starting_ID == 33)
{
count_routes++; //Add 1 into the variable “count_routes”
cout << count_routes << " ";
for(int i= 0; i < pathCount; i++)
{
cout << my_track[i];
}
cout << endl;
return;
}
else //Get into recursive Function Body
{
if(from_track_id >= 0) my_track[from_track_id].visited = 1;
for(int i = my_station[Current_Station_ID].track_starting_ID; i < my_station[Current_Station_ID].track_starting_ID + my_station[Current_Station_ID].track_size; i++)
{
int nextStation = my_track[i].node_2; ///<<<<<<< But you will need to change node_2 to be an int, and use the station number, not letter when you set them up
if(my_track[i].visited == 0)
{
currentPath[pathCount] = my_track[i];
SearchRoute(nextStation, i, currentPath, pathCount + 1);
}
}
if(from_track_id >= 0) my_track[from_track_id].visited = 0;
}
}
int main()
{
Track tempTracks[34];
SubwaySystem findPaths;
findPaths.SearchRoute(0, -1, tempTracks, 0);
}
// RandomTest.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;
class Track
{
public:
//Default Constructor
Track();
//Overload Constructor
Track(char, char, int station, int opposite);
//Destructor
~Track();
//Member variables
char node_1; // node_1 and node_2 represent stations (for example
char node_2; // node_1 would be station A and node_2 would be station B)
bool visited;
int connected_station;
int opposite_track;
};
class Station
{
public:
//Default Constructor
Station();
//Destructor
~Station();
//Overload Constructor
Station(char, int, int);
//Member variables
char station_name;
int track_starting_ID;
int track_size;
};
class SubwaySystem
{
public:
//Default Constructor
SubwaySystem();
//Destructor
~SubwaySystem();
//Recursive function
void SearchRoute(int);
//Other member functions
friend ostream& operator<<(ostream& os, const Track& my_track);
friend ostream& operator<<(ostream& os, const Station& my_station);
//Member variables
Track my_track[34];
Station my_station[12];
int count_routes;
int Current_Station_ID;
//String to save found route
void SearchRoute(int Current_Station_ID, int from_track_id, Track **currentPath, int pathCount);
};
// **cpp**
//#include "subway.h"
using namespace std;
Track::Track()
{
visited = 0;
}
Track::~Track()
{
}
Track::Track(char pass_track1, char pass_track2, int station, int opposite)
{
node_1 = pass_track1;
node_2 = pass_track2;
connected_station = station;
opposite_track = opposite;
visited = false;
}
Station::Station()
{
}
Station::~Station()
{
}
Station::Station(char pass_station_name, int pass_start, int pass_size)
{
station_name = pass_station_name;
track_starting_ID = pass_start;
track_size = pass_size;
}
SubwaySystem::SubwaySystem()
{
//Initialize tracks
//node_1, node_2
my_track[0] = Track('a', 'b', 1, 1);
my_track[1] = Track('b', 'a', 0, 0);
my_track[2] = Track('b', 'c', 2, 6);
my_track[3] = Track('b', 'd', 3, 8);
my_track[4] = Track('b', 'e', 4, 10);
my_track[5] = Track('b', 'f', 5, 15);
my_track[6] = Track('c', 'b', 1, 2);
my_track[7] = Track('c', 'e', 4, 11);
my_track[8] = Track('d', 'b', 1, 3);
my_track[9] = Track('d', 'e', 4, 12);
my_track[10] = Track('e', 'b', 1, 4);
my_track[11] = Track('e', 'c', 2, 7);
my_track[12] = Track('e', 'd', 3, 9);
my_track[13] = Track('e', 'g', 6, 17);
my_track[14] = Track('e', 'h', 7, 19);
my_track[15] = Track('f', 'b', 1, 5);
my_track[16] = Track('f', 'h', 7, 20);
my_track[17] = Track('g', 'e', 4, 13);
my_track[18] = Track('g', 'k', 10, 28);
my_track[19] = Track('h', 'e', 4, 14);
my_track[20] = Track('h', 'f', 5, 16);
my_track[21] = Track('h', 'i', 8, 24);
my_track[22] = Track('h', 'j', 9, 26);
my_track[23] = Track('h', 'k', 10, 29);
my_track[24] = Track('i', 'h', 7, 21);
my_track[25] = Track('i', 'k', 10, 30);
my_track[26] = Track('j', 'h', 7, 22);
my_track[27] = Track('j', 'k', 10, 30);
my_track[28] = Track('k', 'g', 6, 18);
my_track[29] = Track('k', 'h', 7, 23);
my_track[30] = Track('k', 'i', 8, 25);
my_track[31] = Track('k', 'j', 9, 27);
my_track[32] = Track('k', 'l', 11, 33);
my_track[33] = Track('l', 'k', 10, 32);
//Initialize stations
//station_name, track_starting_ID, track_size
my_station[0] = Station('a', 0, 1);
my_station[1] = Station('b', 1, 5);
my_station[2] = Station('c', 6, 2);
my_station[3] = Station('d', 8, 2);
my_station[4] = Station('e', 10, 5);
my_station[5] = Station('f', 15, 2);
my_station[6] = Station('g', 17, 2);
my_station[7] = Station('h', 19, 5);
my_station[8] = Station('i', 24, 2);
my_station[9] = Station('j', 26, 2);
my_station[10] = Station('k', 28, 5);
my_station[11] = Station('l', 33, 1);
//Initiaize other members
count_routes = 0;
Current_Station_ID = 0;
}
SubwaySystem::~SubwaySystem()
{
}
void SubwaySystem::SearchRoute(int Current_Station_ID, int from_track_id, Track **currentPath, int pathCount)
{
if(my_station[Current_Station_ID].track_starting_ID == 33)
{
count_routes++; //Add 1 into the variable “count_routes”
cout << count_routes << " ";
for(int i= 0; i < pathCount; i++)
{
cout << *currentPath[i];
}
cout << endl;
return;
}
else //Get into recursive Function Body
{
for(int i = my_station[Current_Station_ID].track_starting_ID; i < my_station[Current_Station_ID].track_starting_ID + my_station[Current_Station_ID].track_size; i++)
{
//check all the tracks that we have visited before
bool visited = false;
for(int n = 0; n < pathCount; n++)
{
if(currentPath[n] == &my_track[i] || i == currentPath[n]->opposite_track) visited = true;
}
if(!visited)
{
int nextStation = my_track[i].connected_station;
currentPath[pathCount] = &my_track[i];
SearchRoute(nextStation, i, currentPath, pathCount + 1);
}
}
}
}
ostream& operator<<(ostream& os, const Track& my_track)
{
os << my_track.node_1 << '.' << my_track.node_2;
return os;
}
ostream& operator<<(ostream& os, const Station& my_station)
{
os << my_station.station_name << '.' << my_station.track_starting_ID << '.' << my_station.track_size;
return os;
}
//This is where the above recursive function SearchRoute goes. I posted it separately so it's easier to read.
// **main**
//#include "subway.h"
int _tmain(int argc, _TCHAR* argv[])
{
Track *tempTracks[34];
SubwaySystem findPaths;
findPaths.SearchRoute(0, -1, tempTracks, 0);
getchar();
return 0;
}
#include <stdio.h>
const char *connectom[] = {
"B", // A
"ACDEF", // B
"BE", // C
"BE", // D
"CDBGH", // E
"BH", // F
"EK", // G
"EFJKI", // H
"HK", // I
"HK", // J
"HIJGL", // K
"K" // L
};
char tracks[0x100];
char strout[0x100];
void path(char x, char *s) {
*s++ = x;
if(x == 'L') {
*s = 0;
printf("path=%s\n", strout);
} else {
for(const char *p = connectom[x - 'A']; *p; p++) {
unsigned char track_ndx = x > *p? (x << 4) ^ *p : (*p << 4) ^ x;
if(tracks[track_ndx] == 0) {
tracks[track_ndx] = 1;
path(*p, s);
tracks[track_ndx] = 0;
} // if
} // for
} // else
} // path
int main(int argc, char **argv) {
path('A', strout);
} // main