用c语言写求迷宫最短路径长度

要用C语言求解迷宫最短路径长度，可以使用广度优先搜索算法。

首先，需要定义一个二维数组来表示迷宫，例如：

int maze[5][5] = {
    {0, 1, 0, 0, 0},
    {0, 1, 0, 1, 0},
    {0, 0, 0, 0, 0},
    {0, 1, 1, 1, 0},
    {0, 0, 0, 1, 0}
};

其中，0表示可以通行的空格，1表示墙或障碍物。

接下来，定义一个队列来存储每个可达的格子。对于每个可达的格子，存储其所在行列及到起点的步数。

typedef struct {
    int row, col, steps;
} Point;

Point queue[25];
int front = 0, rear = 0;

然后，从起点开始，将其加入队列，并将起点标记为已访问。

Point start = {0, 0, 0};
queue[rear++] = start;
maze[0][0] = 1;

接着，使用循环遍历队列中的每个格子，查找其四周可达的格子，并将其加入队列。

while (front < rear) {
    Point current = queue[front++];
    if (current.row == 4 && current.col == 4) {
        printf("Shortest path length is %d\n", current.steps);
        break;
    }
    if (current.row > 0 && maze[current.row-1][current.col] == 0) {
        Point next = {current.row-1, current.col, current.steps+1};
        queue[rear++] = next;
        maze[current.row-1][current.col] = 1;
    }
    if (current.row < 4 && maze[current.row+1][current.col] == 0) {
        Point next = {current.row+1, current.col, current.steps+1};
        queue[rear++] = next;
        maze[current.row+1][current.col] = 1;
    }
    if (current.col > 0 && maze[current.row][current.col-1] == 0) {
        Point next = {current.row, current.col-1, current.steps+1};
        queue[rear++] = next;
        maze[current.row][current.col-1] = 1;
    }
    if (current.col < 4 && maze[current.row][current.col+1] == 0) {
        Point next = {current.row, current.col+1, current.steps+1};
        queue[rear++] = next;
        maze[current.row][current.col+1] = 1;
    }
}

最后，如果队列为空仍未找到终点，则说明不存在通往终点的路径。

完整代码如下：

#include <stdio.h>

typedef struct {
    int row, col, steps;
} Point;

Point queue[25];
int front = 0, rear = 0;

int maze[5][5] = {
    {0, 1, 0, 0, 0},
    {0, 1, 0, 1, 0},
    {0, 0, 0, 0, 0},
    {0, 1, 1, 1, 0},
    {0, 0, 0, 1, 0}
};

int main() {
    Point start = {0, 0, 0};
    queue[rear++] = start;
    maze[0][0] = 1;
    
    while (front < rear) {
        Point current = queue[front++];
        if (current.row == 4 && current.col == 4) {
            printf("Shortest path length is %d\n", current.steps);
            break;
        }
        if (current.row > 0 && maze[current.row-1][current.col] == 0) {
            Point next = {current.row-1, current.col, current.steps+1};
            queue[rear++] = next;
            maze[current.row-1][current.col] = 1;
        }
        if (current.row < 4 && maze[current.row+1][current.col] == 0) {
            Point next = {current.row+1, current.col, current.steps+1};
            queue[rear++] = next;
            maze[current.row+1][current.col] = 1;
        }
        if (current.col > 0 && maze[current.row][current.col-1] == 0) {
            Point next = {current.row, current.col-1, current.steps+1};
            queue[rear++] = next;
            maze[current.row][current.col-1] = 1;
        }
        if (current.col < 4 && maze[current.row][current.col+1] == 0) {
            Point next = {current.row, current.col+1, current.steps+1};
            queue[rear++] = next;
            maze[current.row][current.col+1] = 1;
        }
    }
    
    if (front >= rear) {
        printf("No path found\n");
    }
    
    return 0;
}