添加 1 个边和数字的新图
new graph with adding 1 edges and number
在为 ACM-Contest 做准备 class 时，我们的老师给了我们一页已解决问题的打印页。在一页上写着，2 以下事实是正确的，但她不会说，why or what:
"with adding new 1 edge to a Directed Graph, how many of these may be
true about number of strongly connected component of this graph?
+) at most 1 unit is increased.
++) at most 1 unit is decreased.
+++) maybe not changed.
++++) maybe decreased by more than 2 units.
任何人都可以与我们的团队一起清楚地扩展它吗？
(+) 为假（根据 "increase at most" 的宽泛解释，即暗示没有减少）并且 (++) 为假且 (++++) 为真，因为如果我们将路径的一端到另一端的反馈弧相加，使其成为一个循环，然后我们从 n 个强组件变为 1。(+++) 显然是正确的。
Before (4 strong components):
* --> * --> * --> *
After version A (1 strong component):
___________________
| |
v |
* --> * --> * --> *
After version B (4 strong components):
___________________
| |
| v
* --> * --> * --> *
在为 ACM-Contest 做准备 class 时，我们的老师给了我们一页已解决问题的打印页。在一页上写着，2 以下事实是正确的，但她不会说，why or what:
"with adding new 1 edge to a Directed Graph, how many of these may be true about number of strongly connected component of this graph?
+) at most 1 unit is increased.
++) at most 1 unit is decreased.
+++) maybe not changed.
++++) maybe decreased by more than 2 units.
任何人都可以与我们的团队一起清楚地扩展它吗？
(+) 为假（根据 "increase at most" 的宽泛解释，即暗示没有减少）并且 (++) 为假且 (++++) 为真，因为如果我们将路径的一端到另一端的反馈弧相加，使其成为一个循环，然后我们从 n 个强组件变为 1。(+++) 显然是正确的。
Before (4 strong components):
* --> * --> * --> *
After version A (1 strong component):
___________________
| |
v |
* --> * --> * --> *
After version B (4 strong components):
___________________
| |
| v
* --> * --> * --> *