Help with Course Schedule II (CSES problemset)

The problem is to print the lexicographically smallest topological sorting of the vertices.
But I don’t really know what’s wrong with my code:

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
int main() {
    int n, m; cin >> n >> m;
    vector<int> graph[n+1];
    int indegree[n+1];
    memset(indegree, 0, sizeof(indegree));
        int a, b; cin >> a >> b;
    priority_queue<int,vector<int>,greater<int>> q;
    vector<int> order;
    for (int i=1; i<=n; i++){
        if (indegree[i] == 0) { q.push(i); }
    while (!q.empty()) {
        int curr =;
        for (int next : graph[curr]){
            if (indegree[next] == 0) { q.push(next); }
	for (int i = 0; i < n; i++) {cout << order[i] << " ";}

This is just the modified version of Topological Sort where I used priority queue which pops the min element to get the lexicographically smallest permutation. But this gives WA for some test cases for example:

Could someone help me where the issue is?