地址:http://codeforces.com/problemset/problem/165/D 题目: D. Beard Graph time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output Let's define a non-oriented connected graph of n vertices and n - 1 edg…
Codeforces Round #112 (Div. 2) C. Another Problem on Strings 题意 给一个01字符串,求包含\(k\)个1的子串个数. 思路 统计字符1的位置,两端用0填充. \(k=0\)需要特判. 代码 C. Another Problem on Strings D. Beard Graph 题意 一棵\(N(N \le 10^5)\)个点的树,每条边被染成黑色或白色,初始都是黑色. \(M(M \le 3 \times 10^5)\)次操作,要么…
Codeforces Round #485 (Div. 2) F. AND Graph 题目连接: http://codeforces.com/contest/987/problem/F Description You are given a set of size $m$ with integer elements between $0$ and $2^{n}-1$ inclusive. Let's build an undirected graph on these integers in…
题目大意 一个含有 n 个顶点的无向图,顶点编号为 1~n.给出一个距离数组:d[i] 表示顶点 i 距离图中某个定点的最短距离.这个图有个限制:每个点的度不能超过 k 现在,请构造一个这样的无向图,要求不能有自环,重边,且满足距离数组和度数限制,输出图中的边:如果无解,输出 -1 数据规模:1 ≤ k < n ≤ 105,0 ≤ d[i] < n 做法分析 第一眼做法:SPFA 或者 BFS,想了想,还是乱搞 根据 d 数组直接构造这个图,因为最短路具有最优子结构,所以,d[i] 为 0…
Supercentral Point time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output One day Vasya painted a Cartesian coordinate system on a piece of paper and marked some set of points (x1, y1), (x2, y2),…
