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#include <algorithm>
#include <fstream>
#include <stack>
#include <vector>
std::ifstream in("sortaret.in");
std::ofstream out("sortaret.out");
std::vector<std::vector<unsigned>> graph;
std::vector<int> index;
std::vector<int> lowlink;
std::vector<bool> isOnStack;
std::vector<unsigned> topologicalOrder;
unsigned count = 0;
std::stack<unsigned> s;
void strongConnect(unsigned n) {
index[n] = count;
lowlink[n] = count;
count++;
isOnStack[n] = true;
s.push(n);
for (unsigned w : graph[n]) {
if (index[w] == -1) {
strongConnect(w);
lowlink[n] = std::min(lowlink[n], lowlink[w]);
} else if (isOnStack[w]) {
lowlink[n] = std::min(lowlink[n], index[w]);
}
}
if (lowlink[n] == index[n]) {
unsigned w = s.top();
s.pop();
isOnStack[w] = false;
if (w != n) out << "Not a DAG!\n";
else topologicalOrder.push_back(w);
}
}
int main() {
unsigned n, m;
in >> n >> m;
graph.reserve(n);
index.reserve(n);
lowlink.reserve(n);
isOnStack.reserve(n);
for (unsigned i = 0; i < n; i++) {
graph.push_back(std::vector<unsigned>());
index.push_back(-1);
lowlink.push_back(-1);
isOnStack.push_back(false);
}
for (unsigned i = 0; i < m; i++) {
unsigned from, to;
in >> from >> to;
graph[from - 1].push_back(to - 1);
}
for (int i = 0; i < n; i++) {
if (index[i] == -1) {
strongConnect(i);
}
}
for (int i = topologicalOrder.size() - 1; i >= 0; i--) {
out << topologicalOrder[i] + 1 << " ";
}
return 0;
}