如何在迷宫中找到最快的路线(C)

如何在迷宫中找到最快的路线(C),c,recursion,maze,C,Recursion,Maze,迷宫被定义为一个正方形矩阵。 例如: int maze[N][N] = { { 1, 1, 1, 1, 1, 1, 1 }, { 0, 1, 0, 1, 0, 0, 1 }, { 0, 1, 0, 1, 1, 1, 1 }, { 0, 1, 0, 0, 0, 1, 1 }, { 0, 1, 1, 1, 0, 1, 1 }, { 0, 0, 1, 0, 1, 1, 1 }, { 1, 1, 1, 1, 0, 1, 1 } }; 你只能在有1的地

迷宫被定义为一个正方形矩阵。 例如:

int maze[N][N] =
  { { 1, 1, 1, 1, 1, 1, 1 },
    { 0, 1, 0, 1, 0, 0, 1 },
    { 0, 1, 0, 1, 1, 1, 1 },
    { 0, 1, 0, 0, 0, 1, 1 },
    { 0, 1, 1, 1, 0, 1, 1 },
    { 0, 0, 1, 0, 1, 1, 1 },
    { 1, 1, 1, 1, 0, 1, 1 } };
你只能在有1的地方走。 你可以向下、向上、向左、向右走一步。 从左上角开始,到右下角结束

输出应该是完成任何迷宫的最小步骤。 我们可以假设至少有一种方法可以完成迷宫。 我已经编辑了代码,我想我已经涵盖了所有内容。。但很明显我遗漏了什么。 谢谢你的帮助

int path_help(int maze[][N], int row, int col, int count)
{
    int copy1[N][N], copy2[N][N], copy3[N][N];
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N; j++)
        {
            copy1[i][j] = maze[i][j];
            copy2[i][j] = maze[i][j];
            copy3[i][j] = maze[i][j];
        }
    }
    int a, b, c, d;
    if (col == 0 || row == 0)
    {
        if (row == N - 1)
        {
            if (maze[row][col + 1] == 1)
            {
                maze[row][col] = 0;
                return path_help(maze, row, col + 1, count + 1);
            }
            else return N*N;
        }
        if (col == N - 1)
        {
            if (maze[row + 1][col] == 1)
            {
                maze[row][col] = 0;
                return path_help(maze, row + 1, col, count + 1);
            }
            else return N*N;
        }
        if (maze[row][col + 1] == 1 && maze[row + 1][col] == 1)
        {
            maze[row][col] = 0;
            copy1[row][col] = 0;
            return min(path_help(copy1, row, col + 1, count + 1),path_help(maze, row + 1, col, count + 1));
    }
    if (maze[row][col + 1] == 0 && maze[row + 1][col] == 1)
    {
        maze[row][col] = 0;
        return path_help(maze, row + 1, col, count + 1);
    }
    if (maze[row + 1][col] == 0 && maze[row][col + 1] == 1)
    {
        maze[row][col] = 0;
        return path_help(maze, row, col + 1, count + 1);
    }
    else return N*N;
}
if (col == N - 1 || row == N - 1)
{
    if (col == N - 1 && row == N - 1) return count;
    if (row == N - 1)
    {
        if (maze[row - 1][col] == 1 && maze[row][col + 1] == 1)
        {
            maze[row][col] = 0;
            copy1[row][col] = 0;
            return min(path_help(copy1, row, col + 1, count + 1), path_help(maze, row - 1, col, count + 1));
        }

        if (maze[row - 1][col] == 0 && maze[row][col + 1] == 1)
        {
            maze[row][col] = 0;
            return path_help(maze, row, col + 1, count + 1);
        }
        if (maze[row][col + 1] == 0 && maze[row - 1][col] == 1)
        {
            maze[row][col] = 0;
            return path_help(maze, row - 1, col, count + 1);
        }
        else return N*N;
    }
    if (col == N - 1)
    {
        if (maze[row + 1][col] == 1 && maze[row][col - 1] == 1)
        {
            maze[row][col] = 0;
            copy1[row][col] = 0;
            return min(path_help(copy1, row, col - 1, count + 1), path_help(maze, row + 1, col, count + 1));
        }

        if (maze[row + 1][col] == 0 && maze[row][col - 1] == 1)
        {
            maze[row][col] = 0;
            return path_help(maze, row, col - 1, count + 1);
        }
        if (maze[row][col - 1] == 0 && maze[row + 1][col] == 1)
        {
            maze[row][col] = 0;
            return path_help(maze, row + 1, col, count + 1);
        }
        else return N*N;
    }
}
if (maze[row + 1][col] == 1)
{
    maze[row][col] = 0;
    a = path_help(maze, row + 1, col, count + 1);
}
else a = N*N;
if (maze[row - 1][col] == 1)
{
    copy1[row][col] = 0;
    b = path_help(copy1, row - 1, col, count + 1);
}
else b = N*N;
if (maze[row][col + 1] == 1)
{
    copy2[row][col] = 0;
    c = path_help(copy2, row, col + 1, count + 1);
}
else c = N*N;
if (maze[row][col - 1] == 1)
{
    copy3[row][col] = 0;
    d = path_help(copy3, row, col - 1, count + 1);
}
else d = N*N;
return min(min(a, b),min( c, d));
int-path\u帮助(int-maze[][N],int-row,int-col,int-count)
{
int copy1[N][N]、copy2[N][N]、copy3[N][N];
对于(int i=0;i

}

从根本上说,这是一个搜索问题。有很多关于如何解决问题的很好的文章,所以我将讨论一些你需要考虑的细节。p> 因为您需要指定最短路径,而不仅仅是一条“非常好”的路径,所以需要检查每一条可能的路径。深度优先搜索是我的建议


最明显的是,这是没有重用的搜索。最短路径将不包含任何循环,也不包含光标将返回到其已到达的位置的任何情况。这使搜索区域保持合理。

如果运行时不是问题,您可以编写一个函数来尝试每个可能的路由,并返回最小值

int path_helper(int maze[][N],int height, int width, int row, int col){
  if(row==height-1 && col == width-1) return 0;
  if(maze[row][col]==0) return height*width;
  if(col<0 || row<0 || row>=height || col>=width) return height*width;
  maze[row][col]=0;
  int maze2[7][7]={{0}};
  for(int i = 0; i < height; i++){
    for(int j = 0; j < width; j++)
      maze2[j][i]=maze[j][i];
  }
  return min(min(path_helper(maze2,height,width,row+1,col),
  path_helper(maze2,height,width,row-1,col)),      min(path_helper(maze2,height,width,row,col+1),path_helper(maze2,height,width,row,col-1)))+1;
}
int-path\u助手(int-maze[][N],int-height,int-width,int-row,int-col){
if(row==height-1&&col==width-1)返回0;
如果(迷宫[行][列]==0)返回高度*宽度;
如果(列=宽度)返回高度*宽度;
迷宫[行][列]=0;
int maze2[7][7]={{0};
对于(int i=0;i

这很难看,但它应该起作用

因为@Jackson链接的问题没有解决方案,这里有一个改进的算法,适用于这个迷宫问题。我将迷宫值
0
视为无法通过,将
1
视为算法的距离

看起来好像
neigh()
函数应该是递归的,但它不是,它只是以同样的方式检查4个邻居。请注意,并不是所有的路径都遵循:对于一个可能是O(不!)的大型迷宫。另外,搜索并不是指向终点:终点是遇到的,算法的这些特性赋予了它的美感

#include <stdio.h>
#include <stdio.h>
#include <limits.h>

#define MSIZE  7                            // matrix/maze dims

enum ntype { virgin, listed, visited };     // for status field

typedef struct {
    int x;                                  // grid position of node
    int y;                                  // grid position of node
    int value;                              // 0 or 1 as defined in maze[][]
    int dist;                               // distance from start node
    int status;                             // enum as above
} node_t;

int maze[MSIZE][MSIZE] =                     // maze definition
  { { 1, 1, 1, 1, 1, 1, 1 },
    { 0, 1, 0, 1, 0, 0, 1 },
    { 0, 1, 0, 1, 1, 1, 1 },
    { 0, 1, 0, 0, 0, 1, 1 },
    { 0, 1, 1, 1, 0, 1, 1 },
    { 0, 0, 1, 0, 1, 1, 1 },
    { 1, 1, 1, 1, 0, 1, 1 } };

node_t node [MSIZE][MSIZE];                 // working array
node_t *list[MSIZE*MSIZE];                  // array of current node pointers
int listlen;                                // num elements in list[]

void neigh(node_t *cptr, int dx, int dy)
// examine one neighbour of node cptr, offset by dx,dy
{
    node_t *nptr;                           // pointer to neighbour
    int dist;                               // accumulated distance from start
    int x = cptr->x + dx;                   // work out neighbour coords
    int y = cptr->y + dy;                   // work out neighbour coords
    if (x < 0 || x >= MSIZE || y < 0 || y >= MSIZE)
        return;                             // failed edge test    
    nptr = &node[y][x];                     // point to neighbour
    if (nptr->value == 0)                   // no-go node
        return;
    if (nptr->status == visited)            // do no re-visit
        return;

    dist = cptr->dist + nptr->value;        // accumulate distance from start
    if (dist < nptr->dist)                  // if it's less than what was known...
        nptr->dist = dist;                  // ...update with the new distance
    if (nptr->status == virgin) {           // if it's never been seen...
        list[listlen++] = nptr;             // ... neighbour to list
        nptr->status = listed;              // and set its status
    }
}

int main(void)
{
    int i, j, smallest, smallind;
    node_t *cptr, *eptr;

    // init the struct array
    for (j=0; j<MSIZE; j++) {
        for (i=0; i<MSIZE; i++) {
            cptr = &node[j][i];             // pointer to the array element
            cptr->value = maze[j][i];       // the maze definition
            cptr->x = i;                    // self's position
            cptr->y = j;                    // self's position
            cptr->dist = INT_MAX;           // distance from start (unknown)
            cptr->status = virgin;          // never examined
        }
    }

    eptr = &node[MSIZE-1][MSIZE-1];         // pointer to end node

    cptr = &node[0][0];                     // pointer to start node
    cptr->dist  = 0;                        // distance of start node from itself!

    // main loop
    while (cptr != eptr) {                  // until we reach the target node
        cptr->status = visited;             // we've been here now
        neigh(cptr,  0, -1);                // examine node above
        neigh(cptr, -1, 0);                 // examine node on left
        neigh(cptr,  1, 0);                 // examine node on right
        neigh(cptr,  0, 1);                 // examine node below

        // find smallest distance of nodes in list[] (won't include virgins)
        smallest = INT_MAX;
        smallind = -1;                      // set invalid marker index
        for (i=0; i<listlen; i++) {
            if (smallest > list[i]->dist) { // compare distance with smallest
                smallest = list[i]->dist;   // remembers the smallest
                smallind = i;               // remembers the list index of smallest
            }
        }
        // take smallest for next time and remove from list
        if(smallind < 0) {                  // -1 was the "marker"
            printf("No route found\n");
            return 1;
        }
        cptr = list[smallind];              // smallest becomes current node
        if (listlen)                        // replace in list with last element...
           list[smallind] = list[--listlen];// ... and reduce list length
    }                                       // now examine this node

    printf("Distance = %d\n", eptr->dist);  // show the distance of the end node
    return 0;
}
编辑链接中描述了算法本身,如果算法中断,肯定会有其他解释可用。我哈
Distance = 12