problems(rs): add “71. Simplify Path”

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

problems/simplify-path.rs

@@ -0,0 +1,49 @@
+struct Solution {}
+impl Solution {
+    pub fn simplify_path(path: String) -> String {
+        let mut simplified_path = Vec::<&str>::new();
+
+        path.split('/').for_each(|seg| {
+            if seg.is_empty() || seg == "." {
+                return;
+            }
+
+            if seg == ".." {
+                simplified_path.pop();
+                return;
+            }
+
+            simplified_path.push(seg);
+        });
+
+        "/".to_owned() + &simplified_path.join("/")
+    }
+}
+
+fn main() {}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn one_directory() {
+        assert_eq!(
+            Solution::simplify_path("/home/".to_owned()),
+            "/home".to_owned()
+        );
+    }
+
+    #[test]
+    fn just_root() {
+        assert_eq!(Solution::simplify_path("/../".to_owned()), "/".to_owned());
+    }
+
+    #[test]
+    fn consecutive_slashes() {
+        assert_eq!(
+            Solution::simplify_path("/home//foo/".to_owned()),
+            "/home/foo".to_owned()
+        );
+    }
+}