js九宫格算法

var grid = [];
var RowCells = 3;

function initGrid() {
    for (var nRow = 0; nRow < RowCells; nRow++) {
        grid[nRow] = [];
        for (var nCol = 0; nCol < RowCells; nCol++) {
            grid[nRow][nCol] = -1;
        }
    }
}

function showGrid() {
    for (var nRow = 0; nRow < RowCells; nRow++) {
        for (var nCol = 0; nCol < RowCells; nCol++) {
            document.write(grid[nRow][nCol] + ' ');
        }
        document.write('<br/>');
    }
}

var position = {
    nRow: 0,
    nCol: 1
}

function fillData() {
    for (var nData = 1; nData <= RowCells * RowCells; nData++) {
        grid[position.nRow][position.nCol] = nData;
        getNextPosition()
    }
}

function getNextPosition() {
    var newRow = (position.nRow - 1 + RowCells) % RowCells;
    var newCol = (position.nCol - 1 + RowCells) % RowCells;
    if (grid[newRow][newCol] == -1) {
        position.nRow = newRow;
        position.nCol = newCol;
    }
    else {
        position.nRow = (position.nRow + 1) % RowCells;
    }
}

initGrid();
fillData();
showGrid();