F - Cowslip Collections http://codeforces.com/blog/entry/43868 这个题解讲的很好... #include<bits/stdc++.h> #define LL long long #define fi first #define se second #define mk make_pair #define PII pair<int, int> #define PLI pair<LL, int> #define…

D. Robot Rapping Results Report 题目连接: http://www.codeforces.com/contest/655/problem/D Description While Farmer John rebuilds his farm in an unfamiliar portion of Bovinia, Bessie is out trying some alternative jobs. In her new gig as a reporter, Bessi…

题目链接: http://www.codeforces.com/contest/655/problem/D 题意: 题目是要求前k个场次就能确定唯一的拓扑序,求满足条件的最小k. 题解: 二分k的取值,做拓扑排序的时候只要每次只有一个元素没有前驱就可以唯一了. #include<iostream> #include<cstring> #include<cstdio> #include<vector> #include<queue> #includ…

E - Intellectual Inquiry 思路:我自己YY了一个算本质不同子序列的方法, 发现和网上都不一样. 我们从每个点出发向其后面第一个a, b, c, d ...连一条边,那么总的不同子序列就是从0号点出发能走出多少条 不同点的路径. dp[ i ]表示是到 i 这个点的不同路径数, 构成的图显然是个DAG,把这个dp出来就好啦.最后补 n个就是贪贪心. 网上的另外两种方法. dp[ i ] 表示[1, i] 的字符串有多少不同子序列. dp[ i ] = dp[i - 1] *…

E. Intellectual Inquiry 题目连接: http://www.codeforces.com/contest/655/problem/E Description After getting kicked out of her reporting job for not knowing the alphabet, Bessie has decided to attend school at the Fillet and Eggs Eater Academy. She has be…

C. Enduring Exodus 题目连接: http://www.codeforces.com/contest/655/problem/C Description In an attempt to escape the Mischievous Mess Makers' antics, Farmer John has abandoned his farm and is traveling to the other side of Bovinia. During the journey, he…

B. Mischievous Mess Makers 题目连接: http://www.codeforces.com/contest/655/problem/B Description It is a balmy spring afternoon, and Farmer John's n cows are ruminating about link-cut cacti in their stalls. The cows, labeled 1 through n, are arranged so…

A. Amity Assessment 题目连接: http://www.codeforces.com/contest/655/problem/A Description Bessie the cow and her best friend Elsie each received a sliding puzzle on Pi Day. Their puzzles consist of a 2 × 2 grid and three tiles labeled 'A', 'B', and 'C'.…

题目链接:http://codeforces.com/contest/655/problem/D 大意是给若干对偏序,问最少需要前多少对关系,可以确定所有的大小关系. 解法是二分答案,利用拓扑排序看是否所有关系被唯一确定.即任意一次只能有1个元素入度为0入队. #include <iostream> #include <vector> #include <algorithm> #include <string> #include <string.h&g…

Problem F: 我是好人4 Description 众所周知,我是好人!所以不会出太难的题,题意很简单 给你n个数,问你1000000000(含1e9)以内有多少个正整数不是这n个数任意一个的倍数 最后友情提供解题代码(我真是太好人了) void solve(int p[], int n) { int ans = 0; for (int i = 1; i <= 1e9; i++) { int fl = 0; for (int j = 0; j < n; j++) { if (i % p[…

E. Devu and Flowers 题目连接: http://codeforces.com/contest/451/problem/E Description Devu wants to decorate his garden with flowers. He has purchased n boxes, where the i-th box contains fi flowers. All flowers in a single box are of the same color (hen…

B. Pasha and Phone   Pasha has recently bought a new phone jPager and started adding his friends' phone numbers there. Each phone number consists of exactly n digits. Also Pasha has a number k and two sequences of length n / k (n is divisible by k) a…

F - Group Projects 题目大意:给你n个物品, 每个物品有个权值ai, 把它们分成若干组, 总消耗为每组里的最大值减最小值之和. 问你一共有多少种分组方法. 思路:感觉刚看到的时候的想法是先排好序, dp[ i ][ j ][ k ]表示已经划分了 i 个, 并且分成了 j 组, 目前为止的总消耗为k的方案总数. 但是这个状态没有办法转移, 题解提供了一种将贡献分段的方法, 比如说原数组为1 2 3 6 7 8 10, 其中一组里面有 1 3 7 8 那么我们不是 直接计算出(8…

F. Group Projects 题目连接: http://www.codeforces.com/contest/626/problem/F Description There are n students in a class working on group projects. The students will divide into groups (some students may be in groups alone), work on their independent piec…

F. Group Projects   There are n students in a class working on group projects. The students will divide into groups (some students may be in groups alone), work on their independent pieces, and then discuss the results together. It takes the i-th stu…

暴力 A - Orchestra import java.io.*; import java.util.*; public class Main { public static void main(String[] args) { Scanner cin = new Scanner (System.in); int r = cin.nextInt (); int c = cin.nextInt (); int n = cin.nextInt (); int k = cin.nextInt ();…

在家补补题   模拟 A - Robot Sequence #include <bits/stdc++.h> char str[202]; void move(int &x, int &y, char ch) { if (ch == 'U') x--; if (ch == 'D') x++; if (ch == 'L') y--; if (ch == 'R') y++; } int main(void) { int n; scanf ("%d", &…

G. Raffles 题目连接: http://www.codeforces.com/contest/626/problem/G Description Johnny is at a carnival which has n raffles. Raffle i has a prize with value pi. Each participant can put tickets in whichever raffles they choose (they may have more than o…

D. Jerry's Protest 题目连接: http://www.codeforces.com/contest/626/problem/D Description Andrew and Jerry are playing a game with Harry as the scorekeeper. The game consists of three rounds. In each round, Andrew and Jerry draw randomly without replaceme…

题意:https://codeforc.es/contest/1209/problem/D 有n个点心,有k个人,每个人都有喜欢的两个点心,现在给他们排个队,一个一个吃,每个人只要有自己喜欢的点心就会吃掉(不会留给后面的人). 如果有人什么都没吃就会不开心,问怎么安排使不开心的人最少. 思路: 看成一个图的问题,点心是节点,人是一条边.对于每个连通块,总会有一个人吃两个点心,其他人吃一个(其中一个是其他人也就吃掉了的). 可以保证这样是最优的,所有每个连通块的答案是连通数 x-1. #defin…

怎么老是垫底啊. 不高兴. 似乎 A 掉一道题总比别人慢一些. A. Paint the Numbers 贪心,从小到大枚举,如果没有被涂色,就新增一个颜色把自己和倍数都涂上. #include<bits/stdc++.h> #define fec(i, x, y) (int i = head[x], y = g[i].to; i; i = g[i].ne, y = g[i].to) #define dbg(...) fprintf(stderr, __VA_ARGS__) #define F…

C. Binary Table 题目连接: http://codeforces.com/problemset/problem/662/C Description You are given a table consisting of n rows and m columns. Each cell of the table contains either 0 or 1. In one move, you are allowed to pick any row or any column and i…

题目链接:http://codeforces.com/contest/626/problem/C 题意就是给你n个分别拿着2的倍数积木的小朋友和m个分别拿着3的倍数积木的小朋友,每个小朋友拿着积木的数量互不相同,求小朋友中拿着最大积木数的最小的情况(有点绕). 那最坏的情况就是2n或者3m,假设最大的积木数为x,x肯定能被2或3整除,那么x/2就是2的倍数个数,x/3就是3的倍数的个数,x/6就是6的倍数的个数. 因为这个数据量很小,那么只要暴力寻找刚好符合x/3 + x/2 - x/6 >=…

C. Lieges of Legendre 题意:给n,m表示有n个为2的倍数,m个为3的倍数:问这n+m个数不重复时的最大值 最小为多少? 数据:(0 ≤ n, m ≤ 1 000 000, n + m > 0) ps:很水的题,主要是策略: 思路:由于里面每隔6就会重复一次,不好直接模拟,并且模拟的效率很低,那就二分吧!二分即上界为2单独的最大倍数与3单独时的最大倍数之和,下界为前面二者的max;之后利用判断是否mid/2 >= n && mid/3 >= m &am…

E - Preorder Test 思路:想到二分答案了之后就不难啦, 对于每个答案用树形dp取check, 如果二分的值是val, dp[ i ]表示 i 这棵子树答案不低于val的可以访问的 最多节点, 第二次dfs求出以每个点为根的答案. #include<bits/stdc++.h> #define LL long long #define fi first #define se second #define mk make_pair #define PII pair<int,…

A. Orchestra time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Paul is at the orchestra. The string section is arranged in an r × c rectangular grid and is filled with violinists with the ex…

D. Factory Repairs 题目连接: http://www.codeforces.com/contest/635/problem/D Description A factory produces thimbles in bulk. Typically, it can produce up to a thimbles a day. However, some of the machinery is defective, so it can currently only produce…

C. XOR Equation 题目连接: http://www.codeforces.com/contest/635/problem/C Description Two positive integers a and b have a sum of s and a bitwise XOR of x. How many possible values are there for the ordered pair (a, b)? Input The first line of the input…

B. sland Puzzle 题目连接: http://www.codeforces.com/contest/635/problem/B Description A remote island chain contains n islands, labeled 1 through n. Bidirectional bridges connect the islands to form a simple cycle - a bridge connects islands 1 and 2, isl…

A. Orchestra 题目连接: http://www.codeforces.com/contest/635/problem/A Description Paul is at the orchestra. The string section is arranged in an r × c rectangular grid and is filled with violinists with the exception of n violists. Paul really likes vio…