[HELP] Dijkstra's Priority Queue Implemenation

help
1

Source : https://usaco.guide/gold/shortest-paths?lang=cpp#tutorial-1

void dijkstra(int src) { // Source and destination
	for (int i = 0; i < N; ++i) dist[i] = LLONG_MAX;
	// Set all distances to infinity

	using T = pair<ll,int>; priority_queue<T,vector<T>,greater<T>> pq;
	dist[src] = 0; // The shortest path from a node to itself is 0
	pq.push({0, src});

	while (pq.size()) {
		ll cdist; int node; tie(cdist, node) = pq.top(); pq.pop();
		if (cdist != dist[node]) continue;
		for (pair<int, int> i : graph[node]) {
			// If we can reach a neighbouring node faster,
			// we update its minimum distance
			if (cdist+i.second < dist[i.first]) {
				pq.push({dist[i.first] = cdist+i.second, i.first});
			}
		}
	}
}

I am not able to understand the explanation given for why removing this line if (cdist != dist[node]) continue; will lead to a time complexity of O(N^2logN)