I'm stepping away with time to spare.

我离开台面了，还有多余的时间。

In your case, you're done quick sorting with time to spare.

在给书排序的例子中，“快速排序”为你节省了大量的时间。

We should arrive in New York with time to spare.

【time】我们应该可以提前到达纽约。

In Japan, it is common to make an effort to arrive with time to spare for an appointment.

在日本，为了预约而努力赶到是很常见的。