摘要：E Boring Segments 双指针加线段树； 线段树维护区间覆盖问题，具体来说每个节点维护区间被完整覆盖的最小次数； 先将线段按照权值从小到大排序，seg[i]指下标i所对应的线段； 对于双指针l，r来说，r向右移的同时将seg[r]对应的线段覆盖，直到覆盖掉整个区间[1,m]，此时再右移l 阅读全文

摘要：A. Boboniu Likes to Color Balls Boboniu gives you r red balls, g green balls, b blue balls, w white balls. He allows you to do the following operation 阅读全文

摘要：A. Donut Shops There are two rival donut shops. The first shop sells donuts at retail: each donut costs a dollars. The second shop sells donuts only i 阅读全文

摘要：A. Shovels and Swords Polycarp plays a well-known computer game (we won't mention its name). In this game, he can craft tools of two types — shovels a 阅读全文