考试的时候用了两个树状数组去优化,暴力修改,树状数组维护修改后区间差值还有最终求和,最后骗了40分.. 这道题有好多种做法,求和好说,最主要的是开方.这道题过的关键就是掌握一点:在数据范围内,最多开方五六次就会变成1,这样以后再修改就不用修改了. ① 线段树打标记 ② 分块打标记 ③ 树状数组+并查集 因为我考试的时候用的树状数组,所以直接打的第三种,相对来说代码量也少一些. 思路:开始时父亲都指向自己,如果变成1,就把父亲指向下一个位置即可.修改的时候相当于跳着修改.代码当中会有注解.…
Power Strings Time Limit: 3000MS Memory Limit: 65536K Total Submissions: 28859 Accepted: 12045 Description Given two strings a and b we define a*b to be their concatenation. For example, if a = "abc" and b = "def" then a*b = "…
传送门 The k-th Largest Group Time Limit: 2000MS Memory Limit: 131072K Total Submissions: 8690 Accepted: 2847 Description Newman likes playing with cats. He possesses lots of cats in his home. Because the number of cats is really huge, Newman wants…
User ainta has a permutation p1, p2, ..., pn. As the New Year is coming, he wants to make his permutation as pretty as possible. Permutation a1, a2, ..., an is prettier than permutation b1, b2, ..., bn, if and only if there exists an integer k (1 ≤ k…
C. Glass Carving time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Leonid wants to become a glass carver (the person who creates beautiful artworks by cutting the glass). He already has a re…