/* Public Service Announcement: Please don't read this code. It's hideous! Just ask me :) -Kishalaya Saha */ var entries = [], magic = []; var rowsum = [], colsum = [], diasum = []; var stack = []; var learning, stacking, flipped; var currentSize, nextRow, nextCol; //Initializes 2d arrays. By Douglas Crockford Array.matrix = function(numrows, numcols) { var arr = []; for (var i=0; i0 && i+j<=size) { cell.style.backgroundColor = "black"; cell.style.color = "white"; cell.innerHTML = i+j; } } else if (!learning) { var inp = document.createElement("INPUT"); inp.setAttribute("type", "number"); inp.id = i + "," + j; cell.appendChild(inp); } } rowsum.push(0); colsum.push(0); } } function findNextCell() { /* In learning mode, determines where the next entry will be placed*/ if (currentSize%2) { if (magic[nextRow-1][nextCol-1]%currentSize) { nextRow = (nextRow==1) ? currentSize: nextRow-1; nextCol = (nextCol==currentSize)? 1 : nextCol+1; } else nextRow++; } else if (currentSize%4) { for (var i=0; icurrentSize/2 + 3) { cell.style.backgroundColor = "orange"; } } } } } //Event Handlers function reset() { if (learning) { if (currentSize%2) learnOdd(); else if (currentSize%4) learnSinglyEven(); else learnDoublyEven(); } else { document.getElementById("message").innerHTML = ""; createTable(currentSize); setKeyup(); } } function show() { //hint/solve button in learn/play mode var mytable = document.getElementById("mytable"); if (learning) { if (isSolved()) return; var target; if (stacking) target = document.getElementById("note"); else target = mytable.rows[nextRow].cells.item(nextCol); var bgclr = target.style.backgroundColor; var count = 0; var myVar = setInterval(function() { target.style.backgroundColor = (target.style.backgroundColor == bgclr) ? "blue" : bgclr; if (++count==6) clearInterval(myVar); }, 500); return; } entries = magicSquare(currentSize, 1, 1); diasum = [0, 0]; for (var i=1; i

First we label each 2×2 block in the grid:

the ones on and above the middle are labelled L,
those right below the middle are labelled U, and
all the ones below them (if any) are labelled X.

Then we interchange the middle U with the L above it.

Now we fill the cells by clicking them, which automatically enters the numbers 1, 2, 3, and so on in sequence. We move from block to block using the Siamese method, starting with the center block of the top row (note that the blocks form a square grid of odd size). Inside each block, we fill the four squares sequentially according to the order presented above (suggested by the shape of the letters).

"; } function play() { learning = false; document.getElementById("home").style.display = "none"; document.getElementById("mytable").style.display = "table"; document.getElementById("controls").style.display = "block"; document.getElementById("resize").style.display = "block"; document.getElementById("guide").innerHTML = "Solve!"; var message = document.getElementById("message"); message.style.display = "block"; message.style.textAlign = "center"; message.innerHTML = ""; currentSize = 5; createTable(currentSize); setKeyup(); } function mainMenu() { document.getElementById("home").style.display = "block"; document.getElementById("mytable").style.display = "none"; document.getElementById("controls").style.display = "none"; document.getElementById("resize").style.display = "none"; document.getElementById("note").style.display = "none"; document.getElementById("message").style.display = "none"; }

Magic Square Tutor