Determinant of quadratic matrix

det.js

function det (argStr) {
	var numbers = argStr.split(' ').map(Number),
		length = Math.sqrt(numbers.length);

	if ((length % 1) !== 0) return false;
	if (length === 1) return numbers[0];
	if (length === 2) return numbers[0] * numbers[3] - numbers[1] * numbers[2];

	var matrica = [];
	for (var i = 0; i < length; i++) {
		for (var j = 0, row = []; j < length; j++)
			row.push(numbers.shift());
		matrica.push(row);
	}

	var detNumber = 0;
	for (var i = 0; i < length; i++) {
		var newArgStr = '';

		for (var j = 1; j < length; j++)
			for (var k = 0; k < length; k++)
				if (k !== i) newArgStr += matrica[j][k] + ' ';

		newArgStr = newArgStr.trim();

		detNumber += Math.pow(-1, i) * matrica[0][i] * det(newArgStr);
	}

	return detNumber;
}

det.min.js

function det(a){var b=a.split(" ").map(Number),c=Math.sqrt(b.length);if(0!==c%1)return!1;if(1===c)return b[0];if(2===c)return b[0]*b[3]-b[1]*b[2];for(var d=[],e=0;c>e;e++){for(var f=0,g=[];c>f;f++)g.push(b.shift());d.push(g)}for(var h=0,e=0;c>e;e++){for(var i="",f=1;c>f;f++)for(var j=0;c>j;j++)j!==e&&(i+=d[f][j]+" ");i=i.trim(),h+=Math.pow(-1,e)*d[0][e]*det(i)}return h}

examples.js

function det(a){var b=a.split(" ").map(Number),c=Math.sqrt(b.length);if(0!==c%1)return!1;if(1===c)return b[0];if(2===c)return b[0]*b[3]-b[1]*b[2];for(var d=[],e=0;c>e;e++){for(var f=0,g=[];c>f;f++)g.push(b.shift());d.push(g)}for(var h=0,e=0;c>e;e++){for(var i="",f=1;c>f;f++)for(var j=0;c>j;j++)j!==e&&(i+=d[f][j]+" ");i=i.trim(),h+=Math.pow(-1,e)*d[0][e]*det(i)}return h}

console.log(det('5 2 3 3 2 2 1 2 5')); // 16
console.log(det('5 2 3 3 2 2 1 2 9')); // 32
console.log(det('1 2 2 3')); // -1
console.log(det('11 25 33 87')); // 132
console.log(det('12 56 8 96 3 78 45 8 33')); // 17916

// | 12  23  44  56  3   112 |
// | 12  11  144 456 233 3   |
// | 897 1   0   124 0   233 |
// | 88  2   4   1   2   3   | = -11887289955588
// | 1   2   1   2   34  56  |
// | 12  55  876 3   112 809 |
console.log(det('12 23 44 56 3 112 12 11 144 456 233 3 897 1 0 124 0 233 88 2 4 1 2 3 1 2 1 2 34 56 12 55 876 3 11 809')); // -11887289955588