Okabe likes to take walks but knows that spies from the Organization could be anywhere; that’s why he wants to know how many different walks he can take in his city safely. Okabe’s city can be represe

题目链接：http://codeforces.com/contest/821/problem/E dp[i][j]=dp[i-1][j-1]+dp[i-1][j]+dp[i-1][j+1]然后构造矩阵转移就行了。。。貌似没啥难度？ 代码： #include<bits/stdc++.h>using namespace std;const int MAXN=105;cons

题目链接：https://vjudge.net/problem/CodeForces-821E 题意： 我们现在位于（0,0）处，目标是走到（K，0）处。 每一次我们都可以从（x，y）走到（x+1，y-1）或者（x+1，y）或者（x+1，y+1）三个位置之一，且 y <= c [ i ] 。 问我们从起点走到终点的行走方案数。 题解： 我也分不清这改叫递推还是DP 总之方程很好写