soulmachine / leetcode

LeetCode题解,151道题完整版。
BSD 3-Clause "New" or "Revised" License
11.27k stars 3.43k forks source link

leetcode/C++/chapDFS.tex line263 seems typo? #61

Open theoneisneo opened 9 years ago

theoneisneo commented 9 years ago

In the end of

leetcode/C++/chapDFS.tex line263 一个$m$行,$n$列的矩阵,机器人从左上走到右下总共需要的步数是$m+n-2$,其中向下走的步数是$m-1$,因此问题变成了在$m+n-2$个操作中,选择$m–1$个时间点向下走,选择方式有多少种。即 $C_{m+n-2}^{m-1}$ 。

$C_{m+n-2}^{m-1} would present like

m - 1 C m + n - 2

But it should be

m + n - 2 C m - 1

Right? Or your country have different usage of C(m, n)?

If it is a typo, please change it to

一个$m$行,$n$列的矩阵,机器人从左上走到右下总共需要的步数是$m+n-2$,其中向下走的步数是$m-1$,因此问题变成了在$m+n-2$个操作中,选择$m–1$个时间点向下走,选择方式有多少种。即 $C_{m-1}^{m+n-2}$