代码

#include <cstdio>
#include <queue>
using namespace std;

struct node {
	int num;
	priority_queue<int, vector<int>, greater<int> > road;
} t[5000+5];

int N,M;
int a[5000+5],nex=1;

void read() {
	scanf("%d%d",&N,&M);
	int n,m,x,y;
	for(n=1;n<=N;n++) {
		t[n].num=n;
	}
	for(m=1;m<=M;m++) {
		scanf("%d%d",&x,&y);
		t[x].road.push(y);
		t[y].road.push(x);
	}
}

void dfs(int n, int from) {
	a[nex++]=n;
	int x;
	while(!t[n].road.empty()) {
		x=t[n].road.top();
		t[n].road.pop();
		if(x!=from) {
			dfs(x,n);
		}
	}
}

void print() {
	int n;
	for(n=1;n<N;n++) {
		printf("%d ",a[n]);
	}
	printf("%d\n",a[N]);
}

int main() {
	read();
	dfs(1,0);
	print();
	fclose(stdin);
	fclose(stdout);
	return 0;
}

评测结果