small addition SUNK COST FALLACY

src/common_subsequence/mod.rs

@@ -172,6 +172,7 @@ mod test {
             println!("for test_wiki is: {:?}", duration);
         }
         // 30/45 micro how dropped to 8/15 im cooked
+        // 1.5/2
 
         {
             let start = Instant::now();
@@ -181,6 +182,7 @@ mod test {
             println!("for test_db is: {:?}", duration);
         }
         // 22/30 micro
+        // 3.9/4.9
         {
             let start = Instant::now();
             test_dbai();
@@ -189,8 +191,10 @@ mod test {
             println!("for test_dbai is: {:?}", duration);
         }
         // 13/28 micro
+        // 3.5/5.8 // im SO COOKED
 
         // success to me 
+        // ABSOLUTE FAILURE
     }
 
     #[test]

src/common_subsequence/monotonic_sequence.rs

@@ -1,7 +1,7 @@
 //! claude cooked
 //! most of code is me? no most of code is claude
 
-use std::cmp::Ordering;
+use std::ops::Range;
 
 #[derive(Default, Debug, Clone, PartialEq)]
 pub struct MonotonicSequence {
@@ -57,14 +57,17 @@ impl MonotonicSequence {
     /// `self.jumps[result of this function]` to get info
     fn get_jump_index(&self, pos: usize) -> usize {
         match self.jumps.binary_search_by(|(jump_point, _value)| {
-            if *jump_point <= pos {
+            // if *jump_point <= pos {
-                Ordering::Less
+            //     Ordering::Less
-            } else {
+            // } else {
-                Ordering::Greater
+            //     Ordering::Greater
-            }
+            // }
+            jump_point.cmp(&pos)
         }) {
             // we are literally At a jump point
+            // never happen point
             Ok(index) => index,
+
             // Below Zero
             Err(0) => 0,
             // debug_assert_ne!(index, 0); // confident
@@ -428,17 +431,58 @@ impl MonotonicSequence {
     }
     pub fn propagate_to_end(&mut self, pos: usize, val: u32) -> Result<(), SequenceError> {
         let len = self.len();
-        let Some(cur) = self.get(pos) else {
+        let Some(cur) = self.get(pos - 1) else {
             return Ok(());
         };
         Self::can_set_mini(pos, val, (cur, cur + 1))?;
-        self.flatten_after(pos);
+        self.flatten_after(pos - 1);
         if val == cur + 1 {
             self.jumps.push((pos, val));
         }
         self.length = len;
         Ok(())
     }
+    pub fn range2(&self, item: u32) -> Option<Range<usize>> {
+        if self.is_empty() {
+            return None;
+        };
+        debug_assert!(self.validate());
+        let jump_index = (item - self.first().unwrap()) as usize;
+        let &(p, v) = self.jumps.get(jump_index)?;
+        assert_eq!(v, item);
+        let p2 = self.jumps.get(jump_index).map_or(self.len(), |(i, _)| *i);
+        return Some(p..p2);
+    }
+
+    // or you can do this:
+    pub fn range(&self, item: u32) -> Option<Range<usize>> {
+        debug_assert!(self.validate());
+        match self
+            .jumps
+            .binary_search_by(|(_indx, value)| value.cmp(&item))
+        {
+            Ok(f) => Some(Range {
+                start: self.jumps[f].0,
+                end: self
+                    .jumps
+                    .get(f + 1)
+                    .map(|&(i, _)| i)
+                    .unwrap_or(self.length),
+            }),
+            // Err(0) => None,
+            // Err(x) if x == self.len() => None,
+            //  Range {
+            //     start: self.jumps.first().map(|&(i, _)| i).unwrap_or(0),
+            //     end: self.jumps.get(1).map(|&(i, _)| i).unwrap_or(self.length),
+            // },
+            Err(_) => None,
+            // no matching values
+            // Range {
+            //     start: self.jumps[x - 1].0,
+            //     end: self.jumps.get(x).map(|&(i, _)| i).unwrap_or(self.length),
+            // },
+        }
+    }
 }
 
 // ai gen testcases: not quite sure because short + not updated with new methods
@@ -580,4 +624,10 @@ mod tests {
             Err(SequenceError::ValueTooHigh { .. })
         ));
     }
+    #[test]
+    fn absolute_devastation() {
+        let c = [0, 0, 0, 1, 1, 1, 2, 2, 2, 3];
+        let mut db = MonotonicSequence::try_from_vec(&c).unwrap();
+        assert!(db.propagate_to_end(3, 2).is_err());
+    }
 }