CSES - Labyrinth

In this problem, we're asked to find and output the shortest path between two nodes. We can't use DFS here because we're looking for the shortest path. Instead, we can use BFS to solve this problem.

Below is a video solution for this problem by Jonathan Paulson. The video uses Python.

(Note: The video solution TLE's on one of the test cases. I think (??) it may be possible to get AC by setting SEEN[rr][cc] to true after line 42, and removing lines 23, 24, and 38. However, I haven't tested this.)

Implementation

#include <bits/stdc++.h>

using namespace std;

#define ii pair<int, int>
#define f first
#define s second
#define mp make_pair

int n, m;