problems(rs): add “547. Number of Provinces”

Signed-off-by: Matej Focko <mfocko@redhat.com>

problems/rs/number-of-provinces.rs

@@ -0,0 +1,64 @@
+use std::collections::VecDeque;
+
+struct Solution {}
+impl Solution {
+    fn bfs(graph: &[Vec<i32>], visited: &mut [bool], u0: usize) {
+        let mut q = VecDeque::new();
+        q.push_back(u0);
+        visited[u0] = true;
+
+        while let Some(u) = q.pop_front() {
+            for v in (0..graph.len()).filter(|&v| graph[u][v] != 0) {
+                if visited[v] {
+                    continue;
+                }
+
+                q.push_back(v);
+                visited[v] = true;
+            }
+        }
+    }
+
+    pub fn find_circle_num(is_connected: Vec<Vec<i32>>) -> i32 {
+        let mut visited = vec![false; is_connected.len()];
+
+        let mut count = 0;
+        for i in 0..is_connected.len() {
+            if visited[i] {
+                continue;
+            }
+
+            Solution::bfs(&is_connected, &mut visited, i);
+            count += 1;
+        }
+
+        count
+    }
+}
+
+fn main() {}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    // Input: isConnected = [[1,1,0],[1,1,0],[0,0,1]]
+    // Output: 2
+    #[test]
+    fn example_1() {
+        assert_eq!(
+            Solution::find_circle_num(vec![vec![1, 1, 0], vec![1, 1, 0], vec![0, 0, 1]]),
+            2
+        );
+    }
+
+    // Input: isConnected = [[1,0,0],[0,1,0],[0,0,1]]
+    // Output: 3
+    #[test]
+    fn example_2() {
+        assert_eq!(
+            Solution::find_circle_num(vec![vec![1, 0, 0], vec![0, 1, 0], vec![0, 0, 1]]),
+            3
+        );
+    }
+}