整数分解 via miloyip(http://weibo.com/1747724431/yc8lfoCmJ)

integer_factorization.js

function f(s, n, i) {
  if (n == 0) return s + "<br/>";
	else {
		var p = (s == "") ? n + "=" : s + "+";
		var m = (s == "") ? n - 1 : n;
		var r = "";
		for (var j = i; j <= m; j++) 
			r += f(p + j, n - j, j);
		return r;
	}
}
function g(n) {
	return f("", n, 1);
}
document.write(g(4));