text recu works

Code/ldpc/src/encoder/dense.rs

@@ -7,6 +7,7 @@ pub struct DenseEncoder {
     pub k: usize,
     pub n: usize,
     pub col_swaps: Vec<(usize, usize)>,
+    pub rank: usize,
 }
 
 impl DenseEncoder {
@@ -33,6 +34,7 @@ impl DenseEncoder {
             k,
             n,
             col_swaps,
+            rank,
         }
     }
 
@@ -48,10 +50,25 @@ impl DenseEncoder {
             .collect();
 
         // Reverse les changement de colonnes
-        for &(c1, c2) in self.col_swaps.iter().rev() {
-            codeword.swap(c1, c2);
-        }
+        // for &(c1, c2) in self.col_swaps.iter().rev() {
+        //     codeword.swap(c1, c2);
+        // }
+        self.g_matrix
+            .apply_inverse_permutation(&mut codeword, &self.col_swaps);
 
         codeword
     }
+
+    pub fn extract_message(&self, decoded_codeword: &[u8]) -> Vec<u8> {
+        let mut working_copy = decoded_codeword.to_vec();
+
+        self.g_matrix
+            .apply_permutation(&mut working_copy, &self.col_swaps);
+
+        let mut message = Vec::with_capacity(self.k);
+        for i in 0..self.k {
+            message.push(working_copy[self.rank + i]);
+        }
+        message
+    }
 }