UVa 10305 Ordering Tasks

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

typedef vector<int> vi;

int n,m;  //n<100
vector<vi> adjList;
vector<bool> visited;
vector<int> tpOrder;

void dfs2(int u){
    visited[u]=true;
    for(int i=0;i<adjList[u].size();i++){
        int v=adjList[u][i];
        if(!visited[v]){
            dfs2(v);
        }
    }
    tpOrder.push_back(u);
}

int main()
{
    while(scanf("%d%d",&n,&m),n||m){
        adjList.assign(104,vi(0));
        visited.assign(104,false);
        tpOrder.clear();

        int a,b;
        for(int i=0;i<m;i++){
            scanf("%d%d",&a,&b);
            adjList[a].push_back(b);
        }
        for(int node=1;node<=n;node++){
            if(!visited[node]){
                dfs2(node);
            }
        }
        //reverse tpOrder
        for(int i=n-1;i>=0;i--){
            printf("%d",tpOrder[i]);
            printf(i>0?" ":"\n");
        }
    }
    return 0;
}