题目链接: C. Vasya and String time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output High school student Vasya got a string of length n as a birthday present. This string consists of letters 'a' and '…

Vasya and String time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output High school student Vasya got a string of length n as a birthday present. This string consists of letters 'a' and 'b' only.…

原题链接 C. Vasya and String High school student Vasya got a string of length n as a birthday present. This string consists of letters 'a' and 'b' only. Vasya denotes beauty of the string as the maximum length of a substring (consecutive subsequence) con…

C. Vasya and String 题目连接: http://www.codeforces.com/contest/676/problem/C Description High school student Vasya got a string of length n as a birthday present. This string consists of letters 'a' and 'b' only. Vasya denotes beauty of the string as th…

C. Vasya and String time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output High school student Vasya got a string of length n as a birthday present. This string consists of letters 'a' and 'b' onl…

C. Vasya and String time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output High school student Vasya got a string of length n as a birthday present. This string consists of letters 'a' and 'b' onl…

C. Vasya and String time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output ->  Link  <- 题目就不贴出来了,链接在上面: 题意:给定n,k,然后是一个长度为n的只含字母a.b的字符串,问至多改变k次使得一个子串字母都相同且长度最大,如所给样例: input 10 1 bbabbabbba output…

High school student Vasya got a string of length n as a birthday present. This string consists of letters 'a' and 'b' only. Vasya denotesbeauty of the string as the maximum length of a substring (consecutive subsequence) consisting of equal letters.…

题目链接:http://codeforces.com/contest/676/problem/C 原题题解链接:http://www.cnblogs.com/vincentX/p/5405468.html 太菜了,昨晚光想着分块,却没考虑做尺取的时候,对于不需要变化的,那对计数器到k不做贡献.早上恍然大悟,5min改出来了…鶸一个. /* ━━━━━┒ギリギリ♂ eye! ┓┏┓┏┓┃キリキリ♂ mind! ┛┗┛┗┛┃＼○/ ┓┏┓┏┓┃ / ┛┗┛┗┛┃ノ) ┓┏┓┏┓┃ ┛┗┛┗┛┃ ┓┏…

题目大概说给一个由a和b组成的字符串,最多能改变其中的k个字符,问通过改变能得到的最长连续且相同的字符串是多长. 用尺取法,改变成a和改变成b分别做一次:双指针i和j,j不停++,然后如果遇到需要改变且改变次数用完就让i++更正改变次数,最后更新答案.时间复杂度O(n). 另外,注意到k=0的情况. #include<cstdio> #include<cstring> #include<algorithm> using namespace std; ]; int mai…

题目链接: http://codeforces.com/contest/676/problem/C 题解: 把连续的一段压缩成一个数,对新的数组求前缀和,用两个指针从左到右线性扫一遍. 一段值改变一部分的情况考虑的不够周到,wa了两次. #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<cmath> #include<vect…

题意: 给出一个长度为n的字符串,只有字符'a'和'b'.最多能改变k个字符,即把'a'变成'b'或把'b'变成'a'. 问改变后的最长连续相同字符的字串长度为多少. 首先是二分查找,好想也好写 ..]of longint; ch:ansistring; n,k,i,l,r,mid,last,ans:longint; function max(x,y:longint):longint; begin if x>y then exit(x); exit(y); end; begin //assign…

题目 Vasya and Kolya play a game with a string, using the following rules. Initially, Kolya creates a string s, consisting of small English letters, and uniformly at random chooses an integer k from a segment [0, len(s) - 1]. He tells Vasya this string…

Codeforces Round #354 (Div. 2) Problems     # Name     A Nicholas and Permutation standard input/output 1 s, 256 MB    x3384 B Pyramid of Glasses standard input/output 1 s, 256 MB    x1462 C Vasya and String standard input/output 1 s, 256 MB    x1393…

贪心 A Nicholas and Permutation #include <bits/stdc++.h> typedef long long ll; const int N = 1e5 + 5; int a[105]; int pos[105]; int main() { int n; scanf ("%d", &n); for (int i=1; i<=n; ++i) { scanf ("%d", a+i); pos[a[i]] =…

C. Vasya and String 题目链接:http://codeforces.com/contest/676/problem/C High school student Vasya got a string of length n as a birthday present. This string consists of letters 'a' and 'b' only. Vasya denotes beauty of the string as the maximum length…

A. Robot Bicorn Attack Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/175/problem/A Description Vasya plays Robot Bicorn Attack. The game consists of three rounds. For each one a non-negative integer amount of points is gi…

Description Vasya plays Robot Bicorn Attack. The game consists of three rounds. For each one a non-negative integer amount of points is given. The result of the game is the sum of obtained points. Vasya has already played three rounds and wrote obtai…

B - Pyramid of Glasses n层杯子,问k分钟能流满多少个杯子?和到香槟一样的过程? 思路:应为水的流速为每分钟一立方体(YY),可以做个转化,把最上层的杯子最原始的容积看成K,每个杯子的满的状态为体积为1,那么只要判断所有杯子体积是否大于1就可以. //#pragma comment(linker, "/STACK:167772160")//手动扩栈~~~~hdu 用c++交 #include <cstdio> #include <cstring&…

http://codeforces.com/contest/676 A. Nicholas and Permutation 题意:有一个从1到n的数列,可以任意对调两个数字一次,问数字1和n所在位置之间的最大距离是多少? 思路:可以选择把数字1和开头的数字对调,或者1和末尾的数字对调,或者n和开头的数字对调,或者n和末尾的数字对调,一共四种对调方法,只需要比较对调之后的下标差的绝对值,取最大的即可. 代码: #include<iostream> #include<cstdio> #…

C. Vasya and String time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output High school student Vasya got a string of length n as a birthday present. This string consists of letters 'a' and 'b' onl…

A. Friends Meeting time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Two friends are on the coordinate axis Ox in points with integer coordinates. One of them is in the point x1 = a, another…

题目描述 Vasya has a string s of length n consisting only of digits 0 and 1. Also he has an array a of length n. Vasya performs the following operation until the string becomes empty: choose some consecutive substring of equal characters, erase it from t…

E - Vasya and Binary String 思路:区间dp + 记忆化搜索 转移方程看上一篇博客. 代码: #pragma GCC optimize(2) #pragma GCC optimize(3) #pragma GCC optimize(4) #include<bits/stdc++.h> using namespace std; #define fi first #define se second #define y1 y11 #define pi acos(-1.0)…

E. Vasya and Binary String 链接 分析: 对于长度为x的一段序列,我们可以dp出消除的过程的最优方案,背包即可. 然后区间dp,可以先合并完所有的点,即没相同的一段区间合并为一个点.设f[i][j][k]表示消完区间[i,j]和这段区间后面k个元素最大值,其中k个元素的颜色与点j的颜色相同. 转移:可以首先将j和后面k个元素消除,然后消除[i,j-1].也可以枚举一个和j颜色相同的点m,然后分别先消除[m+1,r-1],剩下的区间就和后面k个连在一起了,再求出这段区间的…

Codeforces1107E 记忆化dp E. Vasya and Binary String Description: Vasya has a string \(s\) of length \(n\) consisting only of digits 0 and 1. Also he has an array \(a\) of length \(n\). Vasya performs the following operation until the string becomes empt…

比赛的时候又被垃圾题艹翻了啊. 这个题显然是区间dp 考虑怎么转移. 类似消除方块和ZYB玩字符串那样的一个DP. 可以从左到右依次考虑消除. dp[l][r][k][flag]表示区间l,r左边粘着k个flag. 转移方式: 1.考虑强行去继续黏上下一个字符并使k+1. 2.考虑把一段跳过去,让被跳过的这一段自行不与外界产生关系被消除,然后再去消除后面的. 3.直接消除当前粘着的一段,并获得收益. #include<iostream> #include<cctype> #incl…

题目大意: 给定一个0/1字符串,每次你可以将此字符串中一段连续的任意长度的0/1子串消除掉,注意每次消除的子串中只能有0或者1一种字符,消除掉一串长度为i的0/1字符串会得到a[i]的收益,问将这个字符串完全消除的最大收益 Examples Input 7 1101001 3 4 9 100 1 2 3 Output 109 Input 5 10101 3 10 15 15 15 Output 23 第一个样例是1101001 →→ 111001 →→ 11101 →→ 1111 →→ ∅ .…

题意:给你一个长度为n的01串,和一个数组a,你可以每次选择消除一段数字相同的01串,假设消除的长度为len,那么收益为a[len],问最大的收益是多少? 思路:前两天刚做了POJ 1390,和此题很相似:POJ 1390 .我们甚至可以直接套用这个题的状态转移方程.仍然先把01串预处理一下,把相邻的并且数字相同的位合并成一个块.这样,01串就变成了若干个相邻的01块了. 设dp[i][j][k]为处理第i个块到第j个块,并且后面有k个位和第j个块颜色相同,设f[i]为消除长度为i的串的最大收益…

题目传送门 题解: dp[ l ][ r ][ k ] 代表的是[l, r]这段区间内, 前面有k-1个连续的和s[l]相同且连续的字符传进来的最大值. solve( l, r, k) 代表的是处理 区间[L, R],  正在处理 [L, R]这个区间, 前面有k-1个连续的和s[l]相同且连续的字符. 转移状态: dp[l][r][k] = a[k] + solve(l+1,r,1). 在 l 这个位置切断连续字符. dp[l][r][k] = solve( l+1, i-1, 1) + so…