Topological Sort

• Time : O(n)
• Space : O(n)

#include <vector>
using namespace std;

vector<int> topologicalSort(vector<int> jobs, vector<vector<int>> deps) {
  unordered_map<int, vector<int>> adj;
	unordered_map<int, int> ind;
	vector<int> res;
	queue<int> q;
	for(auto& dep : deps) {
		int u = dep[0], v = dep[1];
		ind[v]++;
		adj[u].push_back(v);
	}
	
	for(auto& job : jobs) {
		if(ind[job] == 0)
			q.push(job);
	}
	
	while(!q.empty()) {
		auto u = q.front(); q.pop();
		res.push_back(u);
		for(auto& v : adj[u]) {
			if(--ind[v] == 0)
				q.push(v);
		}
	}
	if(res.size() == jobs.size())
		return res;
	return {};
}