diff -r b8588e318001 -r 8ddf4af937d7 src/de/uapcore/sudoku/Solver.java
--- a/src/de/uapcore/sudoku/Solver.java	Sat Jan 26 18:43:49 2013 +0100
+++ b/src/de/uapcore/sudoku/Solver.java	Sat Jan 26 19:34:31 2013 +0100
@@ -38,11 +38,11 @@
     public boolean check(Field f) {
         int line[];
         for (int i = 0 ; i < 9 ; i++) {
-            line = getRow(f, i);
+            line = f.getRow(i);
             if (!valid(line)) {
                 return false;
             }
-            line = getColumn(f, i);
+            line = f.getColumn(i);
             if (!valid(line)) {
                 return false;
             }
@@ -51,7 +51,7 @@
         int square[][];
         for (int x = 0 ; x < 3 ; x++) {
             for (int y = 0 ; y < 3 ; y++) {
-                square = getSquare(f, x, y);
+                square = f.getSquare(x, y);
                 if (!valid(square)) {
                     return false;
                 }
@@ -82,11 +82,12 @@
     }
     
     private boolean valid(int[] line) {
-        int numbers[] = new int[9];
+        int numbers[];
+        numbers = new int[9];
         for (int i = 0 ; i < 9 ; i++) {
             int l = line[i]-1;
             if (l >= 0) {
-                if (++numbers[l] > 1) {
+                if ((++numbers[l]) > 1) {
                     return false;
                 }
             }
@@ -98,51 +99,8 @@
     private boolean valid(int[][] square) {
         int[] line = new int[9];
         for (int x = 0 ; x < 3 ; x++) {
-            for (int y = 0 ; y < 3 ; y++) {
-                line[3*x+y] = square[x][y];
-            }    
+            System.arraycopy(square[x], 0, line, 3*x, 3);
         }
         return valid(line);
     }
-    
-    private int[][] getSquare(Field f, int x, int y) {
-        if (x < 0 || x > 2 || y < 0 || y > 2) {
-            throw new IllegalArgumentException("Invalid square coordinates");
-        }
-        int[][] square = new int[3][3];
-        
-        for (int u = 0 ; u < 3 ; u++) {
-            for (int v = 0 ; v < 3 ; v++) {
-                square[u][v] = f.getCellValue(3*x+u, 3*y+v);
-            }
-        }
-        
-        return square;
-    }
-    
-    private int[] getRow(Field f, int y) {
-        if (y < 0 || y > 8) {
-            throw new IllegalArgumentException("Invalid row number");
-        }
-        int row[] = new int[9];
-        
-        for (int x = 0 ; x < 9 ; x++) {
-            row[x] = f.getCellValue(x, y);
-        }
-        
-        return row;
-    }
-    
-    private int[] getColumn(Field f, int x) {
-        if (x < 0 || x > 8) {
-            throw new IllegalArgumentException("Invalid column number");
-        }
-        int column[] = new int[9];
-        
-        for (int y = 0 ; y < 9 ; y++) {
-            column[y] = f.getCellValue(x, y);
-        }
-        
-        return column;
-    }
 }