Toposort   问题描述 给出nn个点mm条边的有向无环图. 要求删掉恰好kk条边使得字典序最小的拓扑序列尽可能小. 输入描述 输入包含多组数据. 第一行有一个整数TT, 表示测试数据组数. 对于每组数据: 第一行包含3个整数nn, mm和kk (1 \le n \le 100000, 0 \le k \le m \le 200000)(1≤n≤100000,0≤k≤m≤200000), 表示图中结点数目, 图中边的数目以及要删的边数. 接下来mm行, 每行包含两个整数u_iu​i​​ a…

LCP Array  Accepts: 131  Submissions: 1352  Time Limit: 4000/2000 MS (Java/Others)  Memory Limit: 131072/131072 K (Java/Others) 问题描述 Peter有一个字符串s=s_{1}s_{2}...s_{n}s=s​1​​s​2​​...s​n​​, 令\text{suff}_i =s_{i}s_{i+1}...s_{n}suff​i​​=s​i​​s​i+1​​...s​n​…

Shortest Path  Accepts: 40  Submissions: 610  Time Limit: 4000/2000 MS (Java/Others)  Memory Limit: 131072/131072 K (Java/Others) 问题描述 有一条长度为nn的链. 节点ii和i+1i+1之间有长度为11的边. 现在又新加了3条边, 每条边长度都是1. 给出mm个询问, 每次询问两点之间的最短路. 输入描述 输入包含多组数据. 第一行有一个整数TT, 表示测试数据的组数…

题目传送门 /* DP:这题赤裸裸的dp,dp[i][1/0]表示第i块板放木桩和不放木桩的方案数.状态转移方程: dp[i][1] = dp[i-3][1] + dp[i-3][0] + 1; dp[i][0] = dp[i-1][1] + dp[i-1][0]; 比赛时二维dp写搓了,主要是边界情况的判断出错,比如dp[3][1] = 1,因为第3块放了木桩,其他地方不能再放,dp[3][0]同理 解释一下dp[i][1]的三种情况,可能是前面相隔2个放的方案或者是不放的方案,还有唯独在第i…

E. Editor The development of a text editor is a hard problem. You need to implement an extra module for brackets coloring in text. Your editor consists of a line with infinite length and cursor, which points to the current character. Please note that…

题目链接:Captain Flint and Treasure 题意: 一种操作为 选一个下标 使得ans+=a[i] 且 把a[b[i]]+a[i]   要求每个下标都进行一种这样的操作,问怎么样的操作顺序才能使得ans最大 题解: 在题目面板的输入里面说了这是一个有向无环图,我怎么没看到题目上说这是一个图? 我们可以把那个操作当作一条边,而且那个操作还是单向的,所以就成有向无环图了 如果a[i]>=0,那么肯定需要进行这种操作(因为会增加ans的值).如果a[i]为负数,那么肯定是尽量减少这…

组合 1001 LCP Array 第一题就小难,出题的好像是浙大的大牛? 找到一个规律:a[i] = x, s[i..i+x]都想同.a[i] = a[i+1] + 1 (a[i] > 0),否则就是与后一个颜色不同,方案*25.第一次颜色相同的26种方案. #include <bits/stdc++.h> typedef long long ll; const int N = 1e5 + 5; const int MOD = 1e9 + 7; int a[N]; int main()…

题目地址:http://bestcoder.hdu.edu.cn/contests/contest_showproblem.php?cid=691&pid=1003题意:找出一个字符串满足至少有k个不相同的字母的字串的个数可以注意到 如果 i到j 是满足条件的 则 i到j+1,j+2...n都是满足的,所以可以用尺取法,每次找到满足条件最短的 i,j 然后每次都加上 n-j+1就是答案 #include<bits/stdc++.h> #define inf 0x3f3f3f3f ; u…

题目:Click here 题意:bestcoder 上面有中文题目 分析:令f[i]为最后一个木人桩摆放在i位置的方案,令s[i]为f[i]的前缀和.很容易就能想到f[i]=s[i-3]+1,s[i]=s[i-1]+f[i],而s[n]即是所求答案.本题唯一一个值得注意的点就是当n接近60时会爆int. #include <iostream> #include <cstdio> #include <cmath> typedef long long ll; using…

Transform  Accepts: 7  Submissions: 49  Time Limit: 4000/2000 MS (Java/Others)  Memory Limit: 131072/131072 K (Java/Others) 问题描述 给出nn个整数, 对于一个整数xx, 你可以做如下的操作若干次: + 令xx的二进制表示为\overline{b_{31}b_{30}...b_0}​b​31​​b​30​​...b​0​​​​​, 你可以翻转其中一个位. + 令yy是给出的…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5587 题目大意就是初始有一个1,然后每次操作都是先在序列后面添加一个0,然后把原序列添加到0后面,然后从0到末尾,每一个都加上1. 例如:a0, a1, a2 => a0, a1, a2, 1, a0+1, a1+1, a2+1 题解中是这么说的:“ 其实Ai为i二进制中1的个数.每次变化A{k+2^i}=A{k}+1,(k<2^​i​​)不产生进位,二进制1的个数加1.然后数位dp统计前m个数二…

哈哈哈哈,我就知道这道题目再扔给我,我还是不会,就是这么菜,哈哈哈 一开始官方题解就没搞懂-然后就看了一下别人的代码,水水过就算了.今天拿到-GG: 题意: 一开始,有一张原图,有一条长度为n的链. 节点i和i+1之间有长度为1的边. 现在又新加了3条边, 每条边长度都是1. 给出m个询问, 每次询问两点之间的最短路. 然后让你算出对于每组数据, 输出一个整数S=(∑i=1mi⋅zi) mod (109+7), 其中zi表示第i 组询问的答案. 官方题解: 你可以选择分类讨论, 但是估计可能会写…

题目传送门 题意:判断是否是等比数列 分析:高精度 + 条件:a[i] * a[i+2] == a[i+1] * a[i+1].特殊情况:0 0 0 0 0是Yes的,1 2 0 9 2是No的 代码: /************************************************ * Author :Running_Time * Created Time :2015-9-5 20:06:46 * File Name :C.cpp **********************…

题目传送门 题意:判断是否为哈密顿图 分析:首先一种情况是不合法的:也就是度数为1的点超过2个:合法的有:,那么从度数为1的点开始深搜,如果存在一种走法能够走完n个点那么存在哈密顿路 收获:学习资料 代码: /************************************************ * Author :Running_Time * Created Time :2015-8-29 20:37:34 * File Name :C.cpp *******************…

B. Drazil and Tiles 题目连接: http://codeforces.com/contest/516/problem/B Description Drazil created a following problem about putting 1 × 2 tiles into an n × m grid: "There is a grid with some cells that are empty and some cells that are occupied. You s…

题目链接: 题目 A. Misha and Forest time limit per test 1 second memory limit per test 256 megabytes 问题描述 Let's define a forest as a non-directed acyclic graph (also without loops and parallel edges). One day Misha played with the forest consisting of n ver…

C. ReplacementTime Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/570/problem/C Description Daniel has a string s, consisting of lowercase English letters and period signs (characters '.'). Let's define the operation of replace…

B. Legacy 题目连接: http://codeforces.com/contest/786/problem/B Description Rick 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…

E. Pillars time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Marmot found a row with n pillars. The i-th pillar has the height of hi meters. Starting from one pillar i1, Marmot wants to jump…

https://codeforces.com/contest/1131/problem/D 题意 给你一个n*m二维偏序表,代表x[i]和y[j]的大小关系,根据表构造大小分别为n,m的x[],y[],使得两个数组中最大的数尽量小 题解 按照偏序表,构造出从小到大的拓扑图 如何解决相等的数的偏序关系? 用并查集缩点后再进行拓扑排序 如何解决最大的数最小? 只需要使得同一层的数相同就行,可以一批处理栈中的元素,对于一批栈中的元素产生的新点,先放进一个容器里,然后等到这批栈清空了,再把这个容器中的点…

D. Legacy time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Rick 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…

D. Strip time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Alexandra has a paper strip with n numbers on it. Let's call them ai from left to right. Now Alexandra wants to split it into some p…

题目链接:http://codeforces.com/contest/765/problem/F 题意概述: 给出一个序列,若干组询问,问给出下标区间中两数作差的最小绝对值. 分析: 这个题揭示着数据结构题目世界的真谛...... 在线显然凉凉......考虑离线做法. 本题的主要思想: 首先考虑把所有的询问按照右端点排序,用一个指针扫整个序列,同时考虑i作为一组差的右端可以对右端点大于等于i的询问做出的贡献.我们可以发现,我们扫到当前点i,对于所有询问的右端点大于等于i的询问,如果其左端点小于…

Strip time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Alexandra has a paper strip with n numbers on it. Let's call them ai from left to right. Now Alexandra wants to split it into some piec…

传送门 D. Drazil and Tiles time limit per test 2 seconds memory limit per test 256 megabytes Drazil created a following problem about putting 1 × 2 tiles into an n × m grid: "There is a grid with some cells that are empty and some cells that are occupie…

B. Legacy 题目连接: http://codeforces.com/contest/786/problem/B Description Rick 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…

题目链接:BestCoder Round #81 (div.2) 1003 String 题意 中文题,上有链接.就不贴了. 思路 枚举起点i,计算能够达到k个不同字母的最小下标j,则此时有子串len-j个. 将全部起点的值加起来即是结果. 代码 #include<iostream> #include<algorithm> #include<vector> using namespace std; #define LL long long const int MOD =…

Rikka with Phi  Accepts: 5  Submissions: 66  Time Limit: 16000/8000 MS (Java/Others)  Memory Limit: 131072/131072 K (Java/Others) Problem Description Rikka and Yuta are interested in Phi function (which is known as Euler's totient function). Yuta giv…

Codeforces Round #262 (Div. 2) 1003 C. Present time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Little beaver is a beginner programmer, so informatics is his favorite subject. Soon his info…

Baby Ming and Weight lifting Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 681    Accepted Submission(s): 280 Problem Description Baby Ming is fond of weight lifting. He has a barbell pole(the…