用c语言实现Bellman-Ford算法

以下是用C语言实现Bellman-Ford算法的示例代码：

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

#define MAX_VERTICES 1000
#define MAX_EDGES 1000

typedef struct {
    int source;
    int destination;
    int weight;
} Edge;

int vertices_count, edges_count;
Edge edges[MAX_EDGES];
int distances[MAX_VERTICES];

void BellmanFord(int source) {
    // 初始化距离数组
    for (int i = 0; i < vertices_count; ++i) {
        distances[i] = INT_MAX;
    }
    distances[source] = 0;

    // 执行松弛操作
    for (int i = 0; i < vertices_count - 1; ++i) {
        for (int j = 0; j < edges_count; ++j) {
            int u = edges[j].source;
            int v = edges[j].destination;
            int w = edges[j].weight;
            if (distances[u] != INT_MAX && distances[u] + w < distances[v]) {
                distances[v] = distances[u] + w;
            }
        }
    }

    // 检查是否存在负权回路
    for (int i = 0; i < edges_count; ++i) {
        int u = edges[i].source;
        int v = edges[i].destination;
        int w = edges[i].weight;
        if (distances[u] != INT_MAX && distances[u] + w < distances[v]) {
            printf("Detected negative cycle!\n");
            return;
        }
    }

    // 输出结果
    printf("Vertex   Distance from Source\n");
    for (int i = 0; i < vertices_count; ++i) {
        printf("%d\t\t%d\n", i, distances[i]);
    }
}

int main() {
    // 读取输入
    scanf("%d %d", &vertices_count, &edges_count);
    for (int i = 0; i < edges_count; ++i) {
        scanf("%d %d %d", &edges[i].source, &edges[i].destination, &edges[i].weight);
    }

    // 执行算法
    BellmanFord(0);

    return 0;
}

其中，`BellmanFord`函数表示Bellman-Ford算法的实现，`distances`数组存储每个顶点到源顶点的最短距离，`edges`数组存储所有边的信息。该算法首先初始化距离数组，然后执行`vertices_count - 1`次松弛操作，最后检查是否存在负权回路。如果不存在负权回路，则输出每个顶点到源顶点的最短距离。如果存在负权回路，则输出提示信息。