Method pop

src/class161/Code02_LCA1.java:89–94

()

	}

	public static void pop() {
		--stacksize;
		first = fse[stacksize][0];
		second = fse[stacksize][1];
		edge = fse[stacksize][2];
	}

	// dfs1的迭代版
	public static void dfs3() {