用c语言实现简单地图导航： 1.地图不低于五个点 2.可以在代码里设置好点名，路径，路径权重 3.程序运行，输入两个点，输出最短距离及最短路径

好的，这是一个比较有趣的问题，我可以帮你实现一个简单的地图导航程序。下面是一个示例代码，你可以根据自己的需求进行修改。

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

#define MAX_POINTS 5
#define MAX_NAME_LEN 20

// 点结构体
typedef struct {
    char name[MAX_NAME_LEN];
    int x;
    int y;
} Point;

// 边结构体
typedef struct {
    int from;
    int to;
    int weight;
} Edge;

// 地图结构体
typedef struct {
    int num_points;
    Point points[MAX_POINTS];
    int num_edges;
    Edge edges[MAX_POINTS * (MAX_POINTS - 1) / 2];
} Map;

// 初始化地图
void init_map(Map *map) {
    // 设置点的名称和坐标
    strcpy(map->points[0].name, "A");
    map->points[0].x = 0;
    map->points[0].y = 0;
    strcpy(map->points[1].name, "B");
    map->points[1].x = 1;
    map->points[1].y = 1;
    strcpy(map->points[2].name, "C");
    map->points[2].x = 2;
    map->points[2].y = 2;
    strcpy(map->points[3].name, "D");
    map->points[3].x = 3;
    map->points[3].y = 3;
    strcpy(map->points[4].name, "E");
    map->points[4].x = 4;
    map->points[4].y = 4;

    // 设置边的权重
    map->num_edges = 0;
    for (int i = 0; i < map->num_points; i++) {
        for (int j = i + 1; j < map->num_points; j++) {
            map->edges[map->num_edges].from = i;
            map->edges[map->num_edges].to = j;
            int dx = map->points[i].x - map->points[j].x;
            int dy = map->points[i].y - map->points[j].y;
            map->edges[map->num_edges].weight = dx * dx + dy * dy; // 欧几里得距离的平方
            map->num_edges++;
        }
    }
}

// 查找点的索引
int find_point(Map *map, char *name) {
    for (int i = 0; i < map->num_points; i++) {
        if (strcmp(map->points[i].name, name) == 0) {
            return i;
        }
    }
    return -1;
}

// 查找从from到to的边的索引
int find_edge(Map *map, int from, int to) {
    for (int i = 0; i < map->num_edges; i++) {
        if (map->edges[i].from == from && map->edges[i].to == to) {
            return i;
        }
        if (map->edges[i].from == to && map->edges[i].to == from) {
            return i;
        }
    }
    return -1;
}

// Dijkstra算法
void shortest_path(Map *map, int start, int end, int *path, int *path_len, int *dist) {
    int visited[MAX_POINTS] = {0};
    int prev[MAX_POINTS];
    for (int i = 0; i < map->num_points; i++) {
        dist[i] = INT_MAX;
        prev[i] = -1;
    }
    dist[start] = 0;
    for (int i = 0; i < map->num_points; i++) {
        int min_dist = INT_MAX;
        int min_index = -1;
        for (int j = 0; j < map->num_points; j++) {
            if (!visited[j] && dist[j] < min_dist) {
                min_dist = dist[j];
                min_index = j;
            }
        }
        if (min_index == -1) {
            break;
        }
        visited[min_index] = 1;
        for (int j = 0; j < map->num_points; j++) {
            if (!visited[j]) {
                int edge_index = find_edge(map, min_index, j);
                if (edge_index != -1) {
                    int new_dist = dist[min_index] + map->edges[edge_index].weight;
                    if (new_dist < dist[j]) {
                        dist[j] = new_dist;
                        prev[j] = min_index;
                    }
                }
            }
        }
    }
    *path_len = 0;
    int index = end;
    while (index != -1) {
        path[*path_len] = index;
        (*path_len)++;
        index = prev[index];
    }
    for (int i = 0; i < *path_len / 2; i++) {
        int temp = path[i];
        path[i] = path[*path_len - i - 1];
        path[*path_len - i - 1] = temp;
    }
}

int main() {
    Map map;
    init_map(&map);
    printf("请输入起点名称：");
    char start_name[MAX_NAME_LEN];
    scanf("%s", start_name);
    int start = find_point(&map, start_name);
    if (start == -1) {
        printf("起点不存在！\n");
        return 1;
    }
    printf("请输入终点名称：");
    char end_name[MAX_NAME_LEN];
    scanf("%s", end_name);
    int end = find_point(&map, end_name);
    if (end == -1) {
        printf("终点不存在！\n");
        return 1;
    }
    int path[MAX_POINTS];
    int path_len;
    int dist[MAX_POINTS];
    shortest_path(&map, start, end, path, &path_len, dist);
    printf("最短距离为：%d\n", dist[end]);
    printf("最短路径为：");
    for (int i = 0; i < path_len; i++) {
        printf("%s", map.points[path[i]].name);
        if (i != path_len - 1) {
            printf("->");
        }
    }
    printf("\n");
    return 0;
}

这个程序实现了一个具有五个点的地图，你可以在 `init_map` 函数中设置点的名称和坐标，以及边的权重。程序使用了 Dijkstra 算法来找到最短路径和最短距离。你可以通过输入起点和终点的名称来测试程序的功能。