Starry

将式子拆分成四个查询，注意下标会访问到0，而且当时的答案是0，所以不妨初始化成这样，不然会计算出错的贡献。 #include <bits/stdc++.h> /* #include<ext/pb_ds/assoc_container.hpp> #include<ext/pb_ds/hash_policy.hpp> */ using namespace std; const double eps = 1e-10; const double pi = 3.14159265

#include <bits/stdc++.h> /* #include<ext/pb_ds/assoc_container.hpp> #include<ext/pb_ds/hash_policy.hpp> */ using namespace std; const double eps = 1e-10; const double pi = 3.1415926535897932384626433832795; const double eln = 2.718

好像之前位置的写法是错误的。 #include <bits/stdc++.h> /* #include<ext/pb_ds/assoc_container.hpp> #include<ext/pb_ds/hash_policy.hpp> */ using namespace std; const double eps = 1e-10; const double pi = 3.1415926535897932384626433832795; const double e

会了 //2709 in fact #include <bits/stdc++.h> /* #include<ext/pb_ds/assoc_container.hpp> #include<ext/pb_ds/hash_policy.hpp> */ using namespace std; const double eps = 1e-10; const double pi = 3.1415926535897932384626433832795;

注意图不一定联通 #include <bits/stdc++.h> /* #include<ext/pb_ds/assoc_container.hpp> #include<ext/pb_ds/hash_policy.hpp> */ using namespace std; const double eps = 1e-10; const double pi = 3.1415926535897932384626433832795; const double eln &#x