看到数据范围可以看出此题的时间复杂度和kk有关,自然就想到每个障碍对答案产生了多少贡献。 考虑路径的组合意义:从左下角走到右下角,先不考虑有障碍的情况,显然是(n+m−2m−1)(n+m−2m−1),表示一共走n+m−2n+m−2步,其中m−1m−1步是向右走的。 现在考虑有障碍的情况:先将所有障碍以xx...
we’ll just say that the game takes place on an h × w field, and it is painted in two colors, but not like in chess. Almost all cells of the field are white and only some of them are black. Currently Gerald is finishing a game of giant chess against his friend Pollard...
we'll just say that the game takes place on anh × wfield, and it is painted in two colors, but not like in chess. Almost all cells of the field are white and only some of them are black. Currently Gerald is finishing a game of giant chess against his friend Pollard. ...
Gerald and Giant ChessCF 洛咕 题意:给定一个(H*W(H,W<=1e5))的棋盘,棋盘上只有(N(N<=2000))个格子是黑色的,其他格子都是白色的.在棋盘左上角有一个卒,每一步可以向右或者向下移动一格,并且不能移动到黑色格子中.求这个卒从左上角移动到右下角,一共有多少种可能的路线.答案对(1e9+7)取模. ...
559C - Gerald and Giant Chess #include<bits/stdc++.h> #define ll long long #define PII pair<int,int> using namespace std; const int N = 2e5+10; const int mod = 1e9+7; int inv[N]; int fact[N], infact[N]; void init (int n) ...
cf559C. Gerald and Giant Chess(容斥原理),题意$h\timesw$的网格,有$n$个障碍点,每次可以向右或向下移动求从$(1,1)$到$(h,w)$不经过障碍点的方案数Sol容斥原理从$(1,1)$到$(h,w)$不经过障碍点的方案数为$C(h+w,h)$设$f[i]$表示到达第$i$个黑格子的合法路径的方案
Giant chess is quite common in Geraldion. We will not delve into the rules of the game, we'll just say that the game takes place on an h × w field, and it is painted in two colors, but not like in chess. Almost all cells of the field are white and only some of them are ...
[CF559C] Gerald and Giant ChessDescription 给定一个 (H imes W) 的棋盘,有 (N) 个障碍格子,棋子每次可以向右或者向下移动一步,求从左上角到右下角有多少种不同的路线。(N le 2000) Solution 由于(N) 较小,考虑 dp,设 (f[i]) 表示走到第 (i) 个障碍点(且之前不经过其它任何障碍点)的方案数,...
Giant chess is quite common in Geraldion. We。题目来自【牛客题霸】
CF-559C Gerald and Giant Chess(计数DP) 给定一个 H∗WH∗W的棋盘,棋盘上只有NN 个格子是黑色的,其他格子都是白色的。 在棋盘左上角有一个卒,每一步可以向右或者向下移动一格,并且不能移动到黑色格子中。求这个卒从左上角移动到右下角,一共有多少种可能的路线 1≤H,W≤105,1≤N≤20001≤H,W≤10...