sudokuchecker.code

// Sudoku of format

// | a11 | a12 || b11 | b12 |
// --------------------------
// | a21 | a22 || b21 | b22 |
// ==========================
// | c11 | c12 || d11 | d12 |
// --------------------------
// | c21 | c22 || d21 | d22 |

def checkEquality(e11,e12,e21,e22):
counter = 0
counter = if e11 == e12 then 1 else 0 fi
counter = counter + if e11 == e21 then 1 else 0 fi
counter = counter + if e11 == e22 then 1 else 0 fi
counter = counter + if e12 == e21 then 1 else 0 fi
counter = counter + if e12 == e21 then 1 else 0 fi
counter = counter + if e21 == e22 then 1 else 0 fi
return counter

def sum(e1,e2,e3,e3):
return e1 + e2 + e3 + e4


def main(a11,a12,a21,a22,b11,b12,b21,b22):
// variables naming: box'row''column'
// counter globally counts duplicate entries in boxes, rows and columns
counter = 0

// check box correctnes

  // assert 1,2,3,4 are used as symbols
  10 == sum(a11,a12,a21,a22)
  10 == sum(b11,b12,b21,b22)
  10 == sum(c11,c12,c21,c22)
  10 == sum(d11,d12,d21,d22)

  // no duplicates
  counter = checkEquality(a11,a12,a21,a22)
  counter = counter + checkEquality(b11,b12,b21,b22)
  counter = counter + checkEquality(c11,c12,c21,c22)
  counter = counter + checkEquality(d11,d12,d21,d22)

// check row correctnes

  10 == sum(a11,a12,b11,b22)
  10 == sum(a21,a22,b21,b22)
  10 == sum(c11,c21,d11,d12)
  10 == sum(c21,c22,d21,d22)

  counter = checkEquality(a11,a21,b11,b21)
  counter = counter + checkEquality(a21,a22,b21,b22)
  counter = counter + checkEquality(c11,c21,d11,d12)
  counter = counter + checkEquality(c21,c22,d21,d22)

// check column correctnes

  10 == sum(a11,a21,c11,c21)
  10 == sum(a12,a22,c12,c22)
  10 == sum(b11,b21,d11,d21)
  10 == sum(b12,b22,d12,d22)

  counter = checkEquality(a11,a21,b11,b21)
  counter = counter + checkEquality(a21,a22,b21,b22)
  counter = counter + checkEquality(c11,c21,d11,d12)
  counter = counter + checkEquality(c21,c22,d21,d22)

// assert counter is 0
counter == 0

return 1