ding_ning123的博客

Description\mathscr{Description}Description Solution\mathscr{Solution}Solution 每行是否承接上行仅与此行状态有关，考虑DP dpidp_{i}dpi​表示1−i行最多合法行数1-i行最多合法行数1−i行最多合法行数 用线段树区间修改，区间最大值 #include <bits/stdc++.h> #define ls x<<1 #define rs x<<1|1 #define P pair

Statement DP时初始状态尽量简单 #include <bits/stdc++.h> #define ll long long using namespace std; const ll N=2e5+10,M=1e9+7; ll T,n,k; //sc=sum of all x(even & <=n) C(n,x) /* (x+1)^n=x^n+C(n,1)x^n-1+...+C(n,n-1)x+1 n odd (x-1)^n=x^n-C(n,1)x^n-1+..