题意:给你两个字符串\(s\)和\(t\),保证\(t\)的字典序大于\(s\),求他们字典序中间的字符串. 题解:我们假设题目给的不是字符串,而是两个10禁止的正整数,那么输出他们之间的数只要把他两加起来除\(2\)就行了,那么对于字符串又为何不可呢?我们可以将每个字母看成\(26\)进制的数,像高精度那样模拟加法运算的过程,然后再模拟除\(2\)的过程即可. 代码: int k; string s,t; int c[N]; int d[N]; int main() { ios::sync_w…

Median String time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given two strings ss and tt, both consisting of exactly kk lowercase Latin letters, ss is lexicographically less than …

把字符串看作是26进制的数,从后往前翻译,那么就可以把两个串变成对应的26进制的数字,那么只要把两个数加起来除以二就得到中间的串对应的数了,同理再转化回来就行了.但是这样会有一个问题就是串的长度有2e5,26的2e5次方显然不可求,所以需要对每一位进行手动的加和运算.对于两个串,我们假设a串从后往前的每一位对应的数值为a0, a1, a2...,b串从后往前的每一位对应的数值为b0, b1, b2...对于进制加法,有 扔一下垃圾代码: #include <iostream> #include…

题目传送门 /* 题意:找到一个字符串p,使得它和s,t的不同的总个数相同 贪心:假设p与s相同,奇偶变换赋值,当是偶数,则有答案 */ #include <cstdio> #include <algorithm> #include <cstring> #include <cmath> #include <iostream> using namespace std; ; const int INF = 0x3f3f3f3f; int p[MAXN…

Interesting drink 题目链接: http://codeforces.com/contest/706/problem/B Description Vasiliy likes to rest after a hard work, so you may often meet him in some bar nearby. As all programmers do, he loves the famous drink "Beecola", which can be bough…

http://codeforces.com/contest/1144 A. Diverse Strings A string is called diverse if it contains consecutive (adjacent) letters of the Latin alphabet and each letter occurs exactly once. For example, the following strings are diverse: "fced", &qu…

C. Median Smoothing Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/591/problem/C Description A schoolboy named Vasya loves reading books on programming and mathematics. He has recently read an encyclopedia article that des…

题目连接:http://codeforces.com/contest/676/problem/C 题意:一串字符串,最多改变k次,求最大的相同子串 题解:很明显直接尺取法 #include<cstdio> #include<cstring> #include<cmath> #include<string> #include<set> #include<map> #include<vector> #include<qu…

B. Equidistant String Time Limit: 20 Sec  Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/545/problem/B Description Little Susie loves strings. Today she calculates distances between them. As Susie is a small girl after all, her strings conta…

[Link]:http://codeforces.com/contest/828/problem/C [Description] 让你猜一个字符串原来是什么; 你知道这个字符串的n个子串; 且知道第i个字符t[i],在k[i]个位置出现过; 且告诉你这k[i]个位置在哪里; 数据不会产生矛盾; 让你输出最终的字符串,输出字典序最小的那个; [Solution] 对于输入的n个子串; 对于每个位置; 看看那个位置有没有子串之前出现过,没有的话,就放在那个位置; 否则,如果当前这个子串ti的长度比原…

链接: https://codeforces.com/contest/1265/problem/A 题意: A string is called beautiful if no two consecutive characters are equal. For example, "ababcb", "a" and "abab" are beautiful strings, while "aaaaaa", "abaa&…

题目链接:https://codeforces.com/contest/1385/problem/D 题意 一个小写字母串称为 $c-good\ string$,如果至少满足以下条件之一: 字符串长度为 $1$,包含字母 $c$ 字符串前一半都为字母 $c$,后一半为 $(c+1)-good\ string$ 字符串后一半都为字母 $c$,前一半为 $(c+1)-good\ string$ 计算将一个长为 $n = 2^k$ 的小写字母串变为 $a-good\ string$ 至少需要替换多少个…

题目链接:https://codeforces.com/contest/1265/problem/A 题意 给出一个由 a, b, c, ? 组成的字符串,将 ? 替换为 a, b, c 中的一个字母,问能否字符串中所有相邻字母都不同. 题解 除非一开始字符串就不合法,否则一定可以构造出合法的字符串,因为共有三个字母可选,而替换时最多需要判断前后两个位置. 代码 #include <bits/stdc++.h> using namespace std; void solve() { strin…

        F. Graph Without Long Directed Paths time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given a connected undirected graph consisting of nn vertices and mm edges. There are no…

F. Graph Without Long Directed Paths time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given a connected undirected graph consisting of nn vertices and mm edges. There are no self-lo…

E1. Median on Segments (Permutations Edition) time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output You are given a permutation p1,p2,…,pnp1,p2,…,pn. A permutation of length nn is a sequence suc…

E2 - Median on Segments (General Case Edition) 题目大意:给你一个数组,求以m为中位数的区间个数. 思路:很巧秒的转换,我们把<= m 数记为1, >m的数 记为-1, 求其前缀,  我们将问题转变成求以<= m 的数作为中位数的区间个数, 答案就变为ans(m) - ans(m - 1),我们可以用上面求得的前缀用bit就能求出答案. #include<bits/stdc++.h> #define LL long long #d…

A. Diverse Strings time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output A string is called diverse if it contains consecutive (adjacent) letters of the Latin alphabet and each letter occurs exac…

C. Median Smoothing   A schoolboy named Vasya loves reading books on programming and mathematics. He has recently read an encyclopedia article that described the method of median smoothing (or median filter) and its many applications in science and e…

B. Obsessive String   Hamed has recently found a string t and suddenly became quite fond of it. He spent several days trying to find all occurrences of t in other strings he had. Finally he became tired and started thinking about the following proble…

参考:http://www.cnblogs.com/widsom/p/9290269.html 传送门:http://codeforces.com/contest/1005/problem/E2 题意:求一段数列中,取其中中位数为m的子序列个数有几个: 思路:首先我们可以先求出——序列中大于等于 m的数占多数的子序列——有多少个.然后,再求出序列中大于等于m+1的数占多数的子序列有多少个. 前面序列的个数减去后面的序列个数,就是答案. 显然这两个个数的求法是一样的.具体来说, 因为要计算区间的大…

D. Binary String Minimizing You are given a binary string of length n (i. e. a string consisting of n characters '0' and '1'). In one move you can swap two adjacent characters of the string. What is the lexicographically minimum possible string you c…

You are given a binary string of length nn (i. e. a string consisting of nn characters '0' and '1'). In one move you can swap two adjacent characters of the string. What is the lexicographically minimum possible string you can obtain from the given o…

传送门 题意: 你需要输出一个长度为n的字符序列(由小写字母组成),且这个字符串中至少包含k个不同的字符.另外题目还有要求:给你两个长度为p和q的序列,设字符序列存在s中 那么就会有s[Pi]<=s[P(i+1)]   (i<p) s[Qi]<=s[Q(i+1)]   (i<q)   如果你能找出来满足这些条件的字符串s,就输出YES和s,否则输出NO 这会得到一个非递减字符串 题解: 因为最后的结果是一个非递减字符串,那么肯定对整个字符串s,会有s[i]<=s[i+1] (…

题意:有一个长度为\(n=2^k\)的字符串,对于某个字符\(c\),我们定义他是一个\(c-good\),如果: ​ 1.\(len=1\),并且\(s[1]=c\). ​ 2.\(len>1\),\(s[1]=s[2]=...=s[\frac{len}{2}]=c\),并且另外一半是一个\((c+1)-good\)字符串. ​ 3.\(len>1\),\(s[\frac{len}{2}+1]=s[\frac{len}{2}+2]=...=s[len]=c\),并且另外一半是一个\((c+1…

题意: 给两个串S,T,问能找出多少的S的(a1,b1)(a2,b2)..(ak,bk),使Sa1---Sb1,...Sak---Sbk都包含子串T,其中k>=1,且(a1,b1)...(ak,bk)互不相交. 比如S = "abacaba",T="aba", 当k=1时,(0,6)满足,还有其他只包含一个aba串的也满足,k-2时,(0,2)(3,6)满足,(0,2)(4,6)也满足,(0,3)(4,6)也满足,所以总共有12种. 解法:dp.先用kmp找出…

D. Equalize Them All time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given an array aa consisting of nn integers. You can perform the following operations arbitrary number of times…

D. Equalize Them All time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given an array aa consisting of nn integers. You can perform the following operations arbitrary number of times…

分析: 三个01组合只有八种情况: 000 s001 s010 0011 s100 s101 1110 s111 s 可以看出只有010,101是不稳定的.其他都是稳定的,且连续地出现了1或0,标记为s. 考虑连续的不稳定串的,例子: 11010100   s        s  110100    s    s    1100 只有两种情况,两个边界是不同(11和00)或者相同(11或者00). 前者中间的不稳定串的长度是2*k,且经过k次将变成11110000,而后者的不稳定串的长度是2*k…

题意:有\(n\)个点和\(m\)条无向边,现在让你给你这\(m\)条边赋方向,但是要满足任意一条边的路径都不能大于\(1\),问是否有满足条件的构造方向,如果有,输出一个二进制串,表示所给的边的方向. 题解:我们先单独拿出\(3\)个点来看,选择一个点,那么与它相连的另外两个点到自己的方向一定是相同的,同理,我们可以推广到任意一个点,与它相连的所有点到它的方向必须都是一样的才行,其实到这儿就不难看出可以用二分图染色来写了,然后打个板子就能很愉快的AC啦~ 代码: int n,m; int a,…