problems(rs): add „936. Stamping The Sequence“

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

problems/stamping-the-sequence.rs

@@ -0,0 +1,86 @@
+impl Solution {
+    fn can_stamp(stamp: &Vec<char>, tape: &Vec<char>, i: usize) -> bool {
+        !Solution::is_fully_stamped_section(stamp.len(), &tape, i)
+            && (0..stamp.len())
+                .map(|j| (stamp[j], tape[i + j]))
+                .all(|(s, t)| s == t || t == '?')
+    }
+
+    fn is_fully_stamped_section(length: usize, tape: &Vec<char>, i: usize) -> bool {
+        (i..i + length).all(|j| tape[j] == '?')
+    }
+
+    fn stamp_tape(length: usize, tape: &mut Vec<char>, i: usize) {
+        (i..i + length).for_each(|j| {
+            tape[j] = '?';
+        })
+    }
+
+    pub fn moves_to_stamp(stamp: String, target: String) -> Vec<i32> {
+        // convert stamp to usable interpretation
+        let stamp: Vec<char> = stamp.chars().collect();
+
+        // convert target to a mutable array of characters
+        let mut tape: Vec<char> = target.chars().collect();
+
+        // keep track of stamped indices
+        let mut stamped: Vec<i32> = Vec::new();
+
+        // go over and try to stamp while possible
+        let mut has_changed = true;
+        while has_changed && stamped.len() <= 10 * tape.len() {
+            has_changed = false;
+
+            (0..tape.len() + 1 - stamp.len()).for_each(|i| {
+                if Solution::can_stamp(&stamp, &tape, i) {
+                    Solution::stamp_tape(stamp.len(), &mut tape, i);
+                    stamped.push(i as i32);
+                    has_changed = true;
+                }
+            });
+        }
+
+        if stamped.len() > 10 * tape.len()
+            || !Solution::is_fully_stamped_section(tape.len(), &tape, 0)
+        {
+            stamped.clear();
+        }
+
+        stamped.reverse();
+        stamped
+    }
+}
+struct Solution {}
+
+fn main() {
+    println!("Hello World!");
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_example() {
+        assert_eq!(
+            Solution::moves_to_stamp("abc".to_string(), "ababc".to_string()),
+            vec![0, 2]
+        );
+    }
+
+    #[test]
+    fn test_another_example() {
+        assert_eq!(
+            Solution::moves_to_stamp("abca".to_string(), "aabcaca".to_string()),
+            vec![0, 3, 1]
+        );
+    }
+
+    #[test]
+    fn test_unusable_stamp() {
+        assert_eq!(
+            Solution::moves_to_stamp("stamp".to_string(), "tamps".to_string()),
+            vec![]
+        );
+    }
+}