Traversal of the graph of the data structure (bfs, dfs)

#include<stdio.h>
#include<string.h>
#include<math.h>
#include<stdlib.h>
#include<time.h>
const int maxn = 1e4 + 50;
const int INF = 0x3f3f3f3f;
int head[maxn], cnt = 0;
int n, m;
int vis[maxn];
struct Edge {
    
    
	int to, next, w;
}edge[maxn << 1];
void add(int u, int v, int w) {
    
    
	edge[cnt].to = v;
	edge[cnt].w = w;
	edge[cnt].next = head[u];
	head[u] = cnt++;
}
void init() {
    
    
	for (int i = 0; i < m; ++i) {
    
    
		head[i] = -1;
	}
}
void dfs(int st) {
    
    
	if (st >= n)return;
	if (!vis[st]) {
    
    
		printf("V%d ", st);
		vis[st] = 1;
	}
	for (int i = head[st]; i != -1; i = edge[i].next) {
    
    
		if (!vis[edge[i].to])
			dfs(edge[i].to);
	}
}
int que[maxn];
int pos = 0, p = 0;
void bfs(int st) {
    
    
	que[pos++] = st;
	while (p != pos) {
    
    
		int temp = que[p];
		p++;
		if (vis[temp])continue;
		vis[temp] = 1;
		printf("V%d ", temp);
		for (int i = head[temp]; i != -1; i = edge[i].next) {
    
    
			if (vis[edge[i].to])continue;
			que[pos++] = edge[i].to;
		}
	}
}
int main() {
    
    
	scanf("%d%d", &n, &m);
	init();
	for (int i = 0; i < m; ++i) {
    
    
		int u, v, w;
		scanf("%d%d%d", &u, &v, &w);
		add(u, v, w);
	}
	int st;
	while (~scanf("%d", &st)) {
    
    
		if (st == -1)break;
		memset(vis, 0, sizeof vis);
		if (st < n)
			printf("BFS From V%d:", st);
		bfs(st);
		puts("");
		memset(vis, 0, sizeof vis);
		if (st < n)
			printf("DFS From V%d:", st);
		dfs(st);
		puts("");
	}
	return 0;
}