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