Consider a directed graph G of N nodes and all edges (u→v) such that u < v. It is clear that this graph doesn’t contain any cycles.
Your task is to find the lexicographically largest topological sort of the graph after removing a given list of edges.
A topological sort of a directed graph is a sequence that contains all nodes from 1 to N in some order such that each node appears in the sequence before all nodes reachable from it.
The first line of input contains a single integer T, the number of test cases.
The first line of each test case contains two integers N and M (1 ≤ N ≤ 105) 
, the number of nodes and the number of edges to be removed, respectively.
Each of the next M lines contains two integers a and b (1 ≤ a < b ≤ N), and represents an edge that should be removed from the graph.
No edge will appear in the list more than once.
For each test case, print N space-separated integers that represent the lexicographically largest topological sort of the graph after removing the given list of edges.
3 3 2 1 3 2 3 4 0 4 2 1 2 1 3
3 1 2 1 2 3 4 2 3 1 4
题意：给你一个完全图 只有从小标号到大标号的边 删去m条边 求字典序最大的拓扑排序
题解：set搞一搞。。。
#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<set>
#include<vector>
using namespace std;
struct node{
int num,lab;
bool operator <(const node& a)const{
if(num==a.num)return lab>a.lab;
return num<a.num;
}
}edge[100005];
vector<int>sp[100005];
set<node>sps;
int der[100005];
int main(){
int t;
scanf("%d",&t);
while(t--){
int n,m,i,j,x,y;
scanf("%d%d",&n,&m);
sps.clear();
for(i=1;i<=n;i++){
sp[i].clear();
der[i]=i-1;
}
for(i=1;i<=m;i++){
scanf("%d%d",&x,&y);
sp[x].push_back(y);
sp[y].push_back(x);
der[y]--;
}
for(i=1;i<=n;i++){
sps.insert((node){der[i],i});
}
for(i=1;i<=n;i++){
node f=*sps.begin();
sps.erase(sps.begin());
printf("%d ",f.lab);
for(j=0;j<sp[f.lab].size();j++){
int du=der[sp[f.lab][j]]++;
if(sps.erase((node){du,sp[f.lab][j]}))sps.insert((node){du+1,sp[f.lab][j]});
}
}
printf("\n");
}
return 0;
}