diff --git a/src/main.rs b/src/main.rs
index 0e3282e..23d6609 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,13 +2,14 @@
 #![recursion_limit = "1000000"]
 #![feature(int_roundings)]
 use rand::{thread_rng,Rng};
-use std::{io, collections};
+use std::io;
 mod cursor;
+mod solver;
 mod linked;
 mod cells;
 mod matrix;
 mod sudoku;
-use crate::sudoku::Sudoku;
+use crate::sudoku::{Sudoku,Solver};
 use std::env;
 
 fn main(){
@@ -17,7 +18,7 @@ let mut input = String::new();
 io::stdin().read_line(&mut input).expect("give valid sudoku");
 let split :Vec<&str> = input.split_whitespace().collect();
 let mut sudoku_problem = Sudoku::new(split[0],split[1].parse::<usize>().unwrap(),split[2].parse::<usize>().unwrap());
-let res = sudoku_problem.time_to_solve(Sudoku::solver);
+let res = sudoku_problem.time_to_solve(Solver::solver);
 if let Some(res) = res{
     println!("found {} solutions to the problem",sudoku_problem.solutions);
     let index = thread_rng().gen_range(1..res.len());    
diff --git a/src/matrix.rs b/src/matrix.rs
index 59b8ab9..19a5ed1 100644
--- a/src/matrix.rs
+++ b/src/matrix.rs
@@ -1,8 +1,6 @@
-use rand::{thread_rng,Rng};
+use rand::Rng;
 use crate::cells::Cell;
 use crate::cells::CERO;
-use crate::cursor;
-use crate::cursor::Cursor;
 use crate::linked::Linked;
 
 pub struct Matrix {
@@ -20,12 +18,8 @@ pub struct Matrix {
 impl Matrix {
     pub fn new(rows: usize, cols: usize) -> Matrix {
         let mut matrix = Matrix {
-            horizontal: crate::linked::Linked {
-                links: Vec::with_capacity(cols + 1),
-            },
-            vertical: crate::linked::Linked {
-                links: Vec::with_capacity(rows + 1),
-            },
+            horizontal: Linked::new_with_cap(cols+1),
+            vertical:  Linked::new_with_cap(rows+1),
             sizes: Vec::new(),
             access: Vec::with_capacity(cols + 1),
             covered: Vec::new(),
diff --git a/src/solver.rs b/src/solver.rs
new file mode 100644
index 0000000..66b723b
--- /dev/null
+++ b/src/solver.rs
@@ -0,0 +1,14 @@
+use crate::matrix::Matrix;
+use crate::cells::Cell;
+
+pub trait Solver {
+    fn solver(&mut self) -> Option<Vec<Vec<usize>>>;
+    fn solve(
+        &mut self,
+        matrix: &mut Matrix,
+        partials: &mut Vec<Cell>,
+        ans: &mut Vec<Vec<Vec<usize>>>,
+    );
+}
+
+
diff --git a/src/sudoku.rs b/src/sudoku.rs
index aa16217..c8e2e73 100644
--- a/src/sudoku.rs
+++ b/src/sudoku.rs
@@ -7,17 +7,26 @@ pub struct Sudoku {
     dimension: usize,
     pub(crate) solutions: usize,
     pub(crate) recursion_depth: usize,
-    pub(crate) wanted_ans_num:usize
+    pub(crate) wanted_ans_num: usize,
+}
+pub trait Solver {
+    fn solver(&mut self) -> Option<Vec<Vec<usize>>>;
+    fn solve(
+        &mut self,
+        matrix: &mut Matrix,
+        partials: &mut Vec<Cell>,
+        ans: &mut Vec<Vec<Vec<usize>>>,
+    );
 }
 
 impl Sudoku {
-    pub fn new(sudoku: &str, dimension: usize,answers_wanted:usize) -> Self {
-         Self{
+    pub fn new(sudoku: &str, dimension: usize, answers_wanted: usize) -> Self {
+        Self {
             sudoku: sudoku.to_owned(),
             dimension: dimension,
             solutions: 0usize,
             recursion_depth: 0usize,
-            wanted_ans_num:answers_wanted,
+            wanted_ans_num: answers_wanted,
         }
     }
     fn small_sudoku(&self, sparse: &mut Vec<Vec<usize>>) {
@@ -31,7 +40,7 @@ impl Sudoku {
                     sparse.push(individual);
                 }
             } else {
-                let temp = self.build_one_row(ind, (val_dig as usize));
+                let temp = self.build_one_row(ind, val_dig as usize);
 
                 let tempp: Vec<usize> = temp.into_iter().flatten().collect();
                 sparse.push(tempp);
@@ -137,7 +146,50 @@ impl Sudoku {
         result
     }
 
-    pub fn solver(&mut self) -> Option<Vec<Vec<usize>>> {
+    fn decoder(&self, row: &Vec<usize>) -> (usize, usize) {
+        let possibilities = self.dimension * self.dimension;
+        let cell = row[0];
+        let value = {
+            let ind = row[1] - (possibilities * possibilities);
+            let mut i = ind % possibilities;
+            if i == 0 {
+                i = possibilities
+            }
+            i
+        };
+        (cell, value)
+    }
+    fn ans_to_sudoku_ans(&self, answers: &Vec<Vec<Vec<usize>>>, length: usize) -> Vec<Vec<usize>> {
+        let mut sudokus: Vec<Vec<usize>> = Vec::new();
+        for answer in answers {
+            let mut sudoku = vec![0usize; length];
+            let decoded: Vec<(usize, usize)> = answer
+                .into_iter()
+                .map(|row| self.decoder(row))
+                .collect::<Vec<(usize, usize)>>();
+
+            decoded
+                .into_iter()
+                .map(|info| sudoku[(info.0) - 1] = info.1)
+                .count();
+            sudokus.push(sudoku);
+        }
+        sudokus
+    }
+    pub(crate) fn time_to_solve(
+        &mut self,
+        f: fn(&mut Sudoku) -> Option<Vec<Vec<usize>>>,
+    ) -> Option<Vec<Vec<usize>>> {
+        let start = SystemTime::now();
+        let res = f(self);
+        let end = SystemTime::now();
+        let duration = end.duration_since(start).unwrap();
+        println!("execution time in milliseconds: {}", duration.as_millis());
+        res
+    }
+}
+impl Solver for Sudoku {
+    fn solver(&mut self) -> Option<Vec<Vec<usize>>> {
         let length = self.sudoku.len() as f64;
 
         let sparse = self.sudoku_to_sparse();
@@ -158,7 +210,7 @@ impl Sudoku {
             println!("no answers");
             return None;
         }
-        let result: Vec<Vec<usize>> = self.ans_to_sudoku_ans(&answers, (length as usize));
+        let result: Vec<Vec<usize>> = self.ans_to_sudoku_ans(&answers, length as usize);
         return Some(result);
     }
     fn solve(
@@ -168,7 +220,7 @@ impl Sudoku {
         ans: &mut Vec<Vec<Vec<usize>>>,
     ) {
         //println!("recursion depth: {}", self.recursion_depth);
-        self.recursion_depth +=1;
+        self.recursion_depth += 1;
         //check if matrix is empty
         let mut curr = matrix.horizontal.cursor(CERO);
         if curr.next(&matrix.horizontal) == None {
@@ -180,16 +232,15 @@ impl Sudoku {
             self.solutions += 1;
             return;
         }
-        if self.wanted_ans_num <=ans.len() {
-            return;
-            
+        if self.wanted_ans_num <= ans.len() {
+            return
         }
         // println!("covered: {:?}",matrix.covered);
         // println!("partials: {:?}", partials);
         // println!("sizes : {:?}", matrix.sizes);
         //find the column with the lowest amount of 1s
 
-        let mut col = matrix.get_smallest();
+        let col = matrix.get_smallest();
         // println!("cell: {:?} covered",col);
         matrix.cover(col);
         let mut curr = matrix.vertical.cursor(col);
@@ -206,46 +257,4 @@ impl Sudoku {
         //println!(" total uncover ops: {}",matrix.total_uncovered);
         // println!("total operations: {}",matrix.total_covered+matrix.total_uncovered);
     }
-
-    fn decoder(&self, row: &Vec<usize>) -> (usize, usize) {
-        let possibilities = self.dimension * self.dimension;
-        let cell = row[0];
-        let value = {
-            let ind = row[1] - (possibilities * possibilities);
-            let mut i = ind % possibilities;
-            if i == 0 {
-                i = possibilities
-            }
-            i
-        };
-        (cell, value)
-    }
-    fn ans_to_sudoku_ans(&self, answers: &Vec<Vec<Vec<usize>>>, length: usize) -> Vec<Vec<usize>> {
-        let mut sudokus: Vec<Vec<usize>> = Vec::new();
-        for answer in answers {
-            let mut sudoku = vec![0usize; length];
-            let decoded: Vec<(usize, usize)> = answer
-                .into_iter()
-                .map(|row| self.decoder(row))
-                .collect::<Vec<(usize, usize)>>();
-
-            decoded
-                .into_iter()
-                .map(|info| sudoku[(info.0) - 1] = info.1)
-                .count();
-            sudokus.push(sudoku);
-        }
-        sudokus
-    }
-    pub(crate) fn time_to_solve(
-        &mut self,
-        f: fn(&mut Sudoku) -> Option<Vec<Vec<usize>>>,
-    ) -> Option<Vec<Vec<usize>>> {
-        let start = SystemTime::now();
-        let res = f(self);
-        let end = SystemTime::now();
-        let duration = end.duration_since(start).unwrap();
-        println!("execution time in milliseconds: {}", duration.as_millis());
-        res
-    }
 }