写到一半发现不会计算路数 求大神指导

#include <bits/stdc++.h>
using namespace std;

#define inf 0x3f3f3f3f
struct node{
	int to;
	int val;
};
vector <node>g[1000010];
vector <int >v[1000010]; 
queue <int> q;
int dis[1000010],dis2[1000010];
bool vis[1000010];
int n,m,a,b;

void spfa(int s){
	for(int x=1;x<=n;x++){
		dis[x] = inf;
	}
	dis[s]=0;
	vis[s]=1;
	q.push(s);
	while(!q.empty()){
		int e=q.front();
		q.pop();
		vis[e]=0;
		for(int x=0;x<g[e].size();x++){
			node to=g[e][x];
			if(dis[to.to] > dis[e]+to.val){
				dis[to.to] = dis[e]+to.val;
				if(vis[to.to] == 0){
					vis[to.to] = 1;
					q.push(to.to);
				}
			}
		}
	}
}

int main(){
	cin >> n >> m;
	for(int x=1;x<=m;x++){
		cin >> a >> b;
		g[a].push_back((node){b,1});
		g[b].push_back((node){a,1});
		v[a][b]++;
	}
	spfa(1);
	for(int x=1;x<=n;x++){
		cout << dis[x] << ' ';
	}//调试 
	return 0;
}