GNFS implementation + GF2 gaussian elimination fix

app/FactorizationUI.hs

@@ -1,7 +1,11 @@
 module FactorizationUI (run) where
 
+import System.Exit (exitSuccess)
 import Utils (askChoice, askNumber)
-import Factorization (fermatFactorization, pollardPminus1, dixon)
+import Factorization
+    ( fermatFactorization, pollardPminus1, dixon
+    , gnfsWith, GNFSParams(..), defaultParams
+    )
 
 run :: IO ()
 run = do
@@ -9,13 +13,15 @@ run = do
     putStrLn "1) Fermat factorization"
     putStrLn "2) Pollard p-1"
     putStrLn "3) Dixon"
+    putStrLn "4) General Number Field Sieve (GNFS)"
 
-    choice <- askChoice 3
+    choice <- askChoice 4
 
     case choice of
         1 -> fermatUI
         2 -> pollardUI
         3 -> dixonUI
+        4 -> gnfsUI
         _ -> error "Impossible"
 
 fermatUI :: IO ()
@@ -50,3 +56,45 @@ dixonUI = do
             putStrLn ("n = " ++ show n)
             putStrLn ("p = " ++ show p)
             putStrLn ("q = " ++ show q)
+
+gnfsUI :: IO ()
+gnfsUI = do
+    putStrLn "General Number Field Sieve"
+    putStrLn "Factors a composite n (not a prime or a prime power) into two non-trivial factors."
+    putStrLn "Practical for n up to roughly 30 digits; the running time grows quickly beyond that."
+    n <- askNumber "Enter an integer n > 1:"
+
+    putStrLn "Parameters:"
+    putStrLn "1) Automatic (recommended)"
+    putStrLn "2) Custom"
+    mode <- askChoice 2
+
+    let auto = defaultParams n
+    params <- case mode of
+        1 -> return auto
+        _ -> do
+            putStrLn ("Automatic values for this n: degree = " ++ show (paramDegree auto)
+                      ++ ", bound B = " ++ show (paramRatBound auto)
+                      ++ ", sieve half-width = " ++ show (paramHalfWidth auto))
+            d <- askNumber "Enter the polynomial degree d (odd, 3 or 5):"
+            if d /= 3 && d /= 5
+                then do
+                    putStrLn "The degree must be 3 or 5."
+                    exitSuccess
+                else return ()
+            b <- askNumber "Enter the factor base bound B (used for both bases):"
+            w <- askNumber "Enter the sieve half-width (a ranges over [-w, w]):"
+            return auto { paramDegree    = fromInteger d
+                        , paramRatBound  = b
+                        , paramAlgBound  = b
+                        , paramHalfWidth = fromInteger w
+                        }
+
+    putStrLn "Running GNFS (this may take a while)..."
+    case gnfsWith params n of
+        Left err ->
+            putStrLn ("Error: " ++ err)
+        Right (p, q) -> do
+            putStrLn ("n = " ++ show n)
+            putStrLn ("p = " ++ show p)
+            putStrLn ("q = " ++ show q)