UVA - 10305 拓扑排序

题目地址

//#include <bits/stdc++.h>
#include<stdio.h>
#include<string.h>
#include<string>
#include<math.h>
#include<algorithm>
#include<iostream>
#include<queue>
#include<vector>
#include<stack>
#include<map>
#include<set>
#include<stdlib.h>
#include<time.h>
#include <iomanip>
#define lowbit(x) (x&(-x))
#define inf  0x7fffffff
#define linf 0x7fffffffffffffff
#define mem(x,y) memset(x,y,sizeof(x))
#define fup(i,x,y) for(int i=(x);i<=(y);i++)
#define fdn(i,x,y) for(int i=(x);i>=(y);i--)
#define sp(x) setprecision(x)
#define sd(n) scanf("%d",&n)
#define sdd(n,m) scanf("%d%d",&n,&m)
#define sddd(n,m,k) scanf("%d%d%d",&n,&m,&k)
#define sld(n) scanf("%lld",&n)
#define sldd(n,m) scanf("%lld%lld",&n,&m)
#define slddd(n,m,k) scanf("%lld%lld%lld",&n,&m,&k)
#define sf(n) scanf("%lf",&n)
#define sff(n,m) scanf("%lf%lf",&n,&m)
#define sfff(n,m,k) scanf("%lf%lf%lf",&n,&m,&k)
#define sc(n) scanf("%s",n)
#define pf(x) printf("%d\n",x)
#define pfl(x) printf("%lld\n",x)
#define pff(x) printf("%lf\n",x)
#define debug printf("!!\n");
#define N 1005
#define M 4000009
#define pi acos(-1)
#define eps 1e-2
//cout.setf(ios::fixed);
//freopen("out.txt","w",stdout);// freopen("in.txt","r",stdin);
using namespace std;
typedef long long  ll;
typedef double db;
const int mod=1e9+7;
struct edge
{
    int d,next;
    edge():next(-1){}
}e[N];
int head[N],which;
void add(int x,int y)
{
    e[++which].d=y;
    e[which].next=head[x];
    head[x]=which;
}
int vis[N],a[N],cnt;
int dfs(int x)
{
    vis[x]=-1;
    for(int i=head[x];i!=-1;i=e[i].next)
    {
        int tp=e[i].d;
        if(vis[tp]==-1) return 0;
        else if(!vis[tp]&&!dfs(tp)) return 0;
    }
    vis[x]=1;
    a[cnt--]=x;
    return 1;
}
void solve()
{
    int n,m;
    while(~sdd(n,m)&&n+m)
    {
        cnt=n;
        which=0;
        mem(head,-1);
        mem(vis,0);
        fup(i,1,m)
        {
            int x,y;
            sdd(x,y);
            add(x,y);
        }
        int f=0;
        fup(i,1,n)
        {
            if(!vis[i])
            {
                if(!dfs(i))
                {
                    f=1;
                    break;
                }
            }
        }
        if(!f)
        {
            fup(i,1,n)
                printf("%d%c",a[i],i!=n?' ':'\n');
        }
    }
}
int main()
{
    int tt=1,k=1;
 //   sd(tt);
  //  getchar();
     while(tt--)
    {
        solve();
    }
    return 0;
}