dfs模板

【代码】

dfs模板

#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<queue>
#include<set>
using namespace std;
#define f(i,n) for(int i=1;i<=(n);i++)
#define ll long long
#define INF 1<<30
#define N 100010
#define M 200010
int n,m;
int read()
{
 	int x=0,f=1;char c=getchar();
 	while(!isdigit(c)){if(c=='-')f=-1;c=getchar();}
 	while( isdigit(c)){x=x*10+c-'0';c=getchar();}
 	return x*f;
}
struct xj
{
	int y;
	int next;
	int v;
}map[2*M];
int cnt;
int head[N];
void add_edge(int u,int v,int z)
{
	map[++cnt].y=v;
	map[cnt].v=z;
	map[cnt].next=head[u];
	head[u]=cnt;
}
void dfs(int x,int fa)
{
	for(int i=head[x];i;i=map[i].next)
	{
		if(map[i].y==fa)continue;
		dfs(map[i].y,x);
	}
}
int main()
{
	n=read();
	m=read();
	int u,v,z;
	f(i,m)
	{
		u=read();
		v=read();
		z=read();
	    add_edge(u,v,z);
	    add_edge(v,u,z);
	} 
	dfs(1,0); 
}