xzw777_的博客

D. LegacyRick and his co-workers have made a new radioactive formula and a lot of bad guys are after them. So Rick wants to give his legacy to Morty before bad guys catch them.There are n planets in t...

题目链接:传送门 题目描述:相邻两块颜色相同为同一块，问给定区间内有多少连通块 题解: 很容易想到用线段树做，然后用并查集实现连通块判定。 build时对每一个块进行编号，并且同列相邻合并(给同一编号),然后考虑横向合并(at:此时两个竖向合并已完成),横向合并就简单啦：直接左右儿子编号对应的L,R丢并查集，左右两块交界处就是mid和mid+1，a[i][mid