很明显的区间K覆盖模型,用费用流求解.只是这题N可达1e5,需要将点离散化. 建模方式步骤: 1.对权值为w的区间[u,v],加边id(u)->id(v+1),容量为1,费用为-w; 2.对所有相邻的点加边id(i)->id(i+1),容量为正无穷,费用为0; 3.建立源点汇点,由源点s向最左侧的点加边,容量为K,费用为0,由最右侧的点向汇点加边,容量为K,费用为0 4.跑出最大流后,最小费用取绝对值就是能获得的最大权 #include<bits/stdc++.h> using n…

God Water likes to eat meat, fish and chocolate very much, but unfortunately, the doctor tells him that some sequence of eating will make them poisonous. Every hour, God Water will eat one kind of food among meat, fish and chocolate. If there are 3 c…

这场打得还是比较爽的,但是队友差一点就再过一题,还是难受啊. 每天都有新的难过 A. Magic Mirror Jessie has a magic mirror. Every morning she will ask the mirror: 'Mirror mirror tell me, who is the most beautiful girl in the world?' If the mirror says her name, she will praise the mirror: '…

A prince of the Science Continent was imprisoned in a castle because of his contempt for mathematics when he was young, and was entangled in some mathematical curses. He studied hard until he reached adulthood and decided to use his knowledge to esca…

There are N children in kindergarten. Miss Li bought them NNN candies. To make the process more interesting, Miss Li comes up with the rule: All the children line up according to their student number (1...N), and each time a child is invited, Miss Li…

Jessie and Justin want to participate in e-sports. E-sports contain many games, but they don't know which one to choose, so they use a way to make decisions. They have several boxes of candies, and there are ii candies in the i^{th}ith box, each cand…

There are NN different kinds of transport ships on the port. The i^{th}ith kind of ship can carry the weight of V[i]V[i] and the number of the i^{th}ith kind of ship is 2^{C[i]} - 12C[i]−1. How many different schemes there are if you want to use thes…

God Water likes to eat meat, fish and chocolate very much, but unfortunately, the doctor tells him that some sequence of eating will make them poisonous. Every hour, God Water will eat one kind of food among meat, fish and chocolate. If there are 33 …

Bob is a sorcerer. He lives in a cuboid room which has a length of AA, a width of BB and a height of CC, so we represent it as AA * BB * CC. One day, he finds that his room is filled with unknown dark energy. Bob wants to neutralize all the dark ener…

Now you have a string consists of uppercase letters, two integers AA and BB. We call a substring wonderful substring when the times it appears in that string is between AA and BB (A \le times \le BA≤times≤B). Can you calculate the number of wonderful…