用C语言写一个广度优先遍历和深度优先遍历

广度优先遍历和深度优先遍历是常见的遍历算法，下面是用 C 语言写的示例代码：

广度优先遍历：

#include <stdio.h>

#define MAX_QUEUE_SIZE 100

int graph[MAX_QUEUE_SIZE][MAX_QUEUE_SIZE];
int visited[MAX_QUEUE_SIZE] = {0};
int queue[MAX_QUEUE_SIZE];
int front = -1, rear = -1;

void bfs(int start, int n) {
    visited[start] = 1;
    queue[++rear] = start;

    while (front != rear) {
        int u = queue[++front];

        printf("%d ", u);

        for (int v = 0; v < n; v++) {
            if (graph[u][v] && !visited[v]) {
                visited[v] = 1;
                queue[++rear] = v;
            }
        }
    }
}

int main() {
    int n, start;
    printf("Enter the number of vertices: ");
    scanf("%d", &n);

    printf("Enter the adjacency matrix:\n");
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            scanf("%d", &graph[i][j]);
        }
    }

    printf("Enter the starting vertex: ");
    scanf("%d", &start);

    printf("BFS traversal: ");
    bfs(start, n);

    return 0;
}

深度优先遍历：

#include <stdio.h>

#define MAX_STACK_SIZE 100

int graph[MAX_STACK_SIZE][MAX_STACK_SIZE];
int visited[MAX_STACK_SIZE] = {0};
int stack[MAX_STACK_SIZE];
int top = -1;

void dfs(int start, int n) {
    visited[start] = 1;
    stack[++top] = start;

    printf("%d ", start);

    for (int v = 0; v < n; v++) {
        if (graph[start][v] && !visited[v]) {
            dfs(v, n);
        }
    }

    top--;
}

int main() {
    int n, start;
    printf("Enter the number of vertices: ");
    scanf("%d", &n);

    printf("Enter the adjacency matrix:\n");
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            scanf("%d", &graph[i][j]);
        }
    }

    printf("Enter the starting vertex: ");
    scanf("%d", &start);

    printf("DFS traversal: ");
    dfs(start, n);

    return 0;
}

希望这可以帮助你理解广度优先遍历和深度优先遍历的算法。