用户自定义迷宫地图，指定入口和出口，采用图相关算法寻找一条出入口之间最短路径用C语言写

以下是采用Dijkstra算法寻找最短路径的C语言代码实现：

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

#define MAX_SIZE 100

typedef struct {
    int x; //横坐标
    int y; //纵坐标
} Point;

typedef struct {
    Point point; //点的坐标
    int dist; //起点到该点的距离
    bool visited; //该点是否已被访问
} Vertex;

Vertex graph[MAX_SIZE][MAX_SIZE]; //图

int rows, cols; //地图的行数和列数

//获取指定点的邻接点
void getNeighbors(Point point, Point neighbors[])
{
    int i, j, cnt = 0;
    for (i = -1; i <= 1; i++) {
        for (j = -1; j <= 1; j++) {
            if (i == 0 && j == 0) continue;
            int x = point.x + i;
            int y = point.y + j;
            if (x >= 0 && x < rows && y >= 0 && y < cols) {
                if (!graph[x][y].visited) {
                    neighbors[cnt++] = (Point){x, y};
                }
            }
        }
    }
}

//计算两点之间的距离
int getDistance(Point p1, Point p2)
{
    int dx = p1.x - p2.x;
    int dy = p1.y - p2.y;
    return dx * dx + dy * dy;
}

//查找当前未访问的距离起点最近的点
Vertex* getMinVertex()
{
    int i, j;
    Vertex* minVertex = NULL;
    int minDist = -1;
    for (i = 0; i < rows; i++) {
        for (j = 0; j < cols; j++) {
            if (!graph[i][j].visited && graph[i][j].dist >= 0) {
                if (minDist < 0 || graph[i][j].dist < minDist) {
                    minDist = graph[i][j].dist;
                    minVertex = &graph[i][j];
                }
            }
        }
    }
    return minVertex;
}

//使用Dijkstra算法寻找最短路径
void findShortestPath(Point start, Point end)
{
    int i, j;
    //初始化每个点的起点距离和是否已访问
    for (i = 0; i < rows; i++) {
        for (j = 0; j < cols; j++) {
            graph[i][j].point = (Point){i, j};
            graph[i][j].dist = -1;
            graph[i][j].visited = false;
        }
    }
    graph[start.x][start.y].dist = 0;
    //循环查找最短路径
    while (true) {
        Vertex* currVertex = getMinVertex();
        if (currVertex == NULL) break;
        currVertex->visited = true;
        if (currVertex->point.x == end.x && currVertex->point.y == end.y) break;
        Point neighbors[8];
        getNeighbors(currVertex->point, neighbors);
        for (i = 0; i < 8; i++) {
            if (neighbors[i].x >= 0 && neighbors[i].y >= 0) {
                int dist = currVertex->dist + getDistance(currVertex->point, neighbors[i]);
                if (graph[neighbors[i].x][neighbors[i].y].dist < 0 || dist < graph[neighbors[i].x][neighbors[i].y].dist) {
                    graph[neighbors[i].x][neighbors[i].y].dist = dist;
                }
            }
        }
    }
    //输出最短路径和距离
    printf("Shortest distance from (%d, %d) to (%d, %d) is %d\n", start.x, start.y, end.x, end.y, graph[end.x][end.y].dist);
    printf("Shortest path: ");
    Vertex* currVertex = &graph[end.x][end.y];
    while (currVertex != NULL) {
        printf("(%d, %d) ", currVertex->point.x, currVertex->point.y);
        Point neighbors[8];
        getNeighbors(currVertex->point, neighbors);
        int minDist = -1;
        Vertex* nextVertex = NULL;
        for (i = 0; i < 8; i++) {
            if (neighbors[i].x >= 0 && neighbors[i].y >= 0) {
                if (graph[neighbors[i].x][neighbors[i].y].dist >= 0) {
                    int dist = getDistance(currVertex->point, neighbors[i]) + graph[neighbors[i].x][neighbors[i].y].dist;
                    if (minDist < 0 || dist < minDist) {
                        minDist = dist;
                        nextVertex = &graph[neighbors[i].x][neighbors[i].y];
                    }
                }
            }
        }
        currVertex = nextVertex;
    }
}

int main()
{
    int i, j;
    //读入地图
    printf("Enter the number of rows and columns: ");
    scanf("%d %d", &rows, &cols);
    printf("Enter the map:\n");
    for (i = 0; i < rows; i++) {
        for (j = 0; j < cols; j++) {
            char c;
            do {
                c = getchar();
            } while (c != '.' && c != 'S' && c != 'E');
            if (c == 'S') {
                graph[i][j].dist = 0;
                graph[i][j].visited = true;
            } else if (c == 'E') {
                graph[i][j].visited = false;
            } else {
                graph[i][j].visited = false;
            }
        }
        getchar(); //消耗行末换行符
    }
    //查找起点和终点
    Point start, end;
    for (i = 0; i < rows; i++) {
        for (j = 0; j < cols; j++) {
            if (graph[i][j].dist >= 0) {
                start = (Point){i, j};
            } else if (!graph[i][j].visited) {
                end = (Point){i, j};
            }
        }
    }
    //查找最短路径
    findShortestPath(start, end);
    return 0;
}

该程序从标准输入读入地图，其中"."表示可通过的格子，"S"表示起点，"E"表示终点。输出起点到终点的最短距离和路径。