zoukankan      html  css  js  c++  java
  • Codeforces Round #533 (Div. 2) B. Zuhair and Strings 【模拟】

    传送门:http://codeforces.com/contest/1105/problem/B

    B. Zuhair and Strings
    time limit per test
    1 second
    memory limit per test
    256 megabytes
    input
    standard input
    output
    standard output

    Given a string ss of length nn and integer kk (1kn1≤k≤n). The string ss has a level xx, if xx is largest non-negative integer, such that it's possible to find in ss:

    • xnon-intersecting (non-overlapping) substrings of length kk,
    • all characters of these xx substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).

    A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers ii and jj (1ijn1≤i≤j≤n), denoted as s[ij]s[i…j]= "sisi+1sjsisi+1…sj".

    For example, if k=2k=2, then:

    • the string "aabb" has level 11 (you can select substring "aa"),
    • the strings "zzzz" and "zzbzz" has level 22 (you can select two non-intersecting substrings "zz" in each of them),
    • the strings "abed" and "aca" have level 00 (you can't find at least one substring of the length k=2k=2 containing the only distinct character).

    Zuhair gave you the integer kk and the string ss of length nn. You need to find xx, the level of the string ss.

    Input

    The first line contains two integers nn and kk (1kn21051≤k≤n≤2⋅105) — the length of the string and the value of kk.

    The second line contains the string ss of length nn consisting only of lowercase Latin letters.

    Output

    Print a single integer xx — the level of the string.

    Examples
    input
    Copy
    8 2
    aaacaabb
    
    output
    Copy
    2
    
    input
    Copy
    2 1
    ab
    
    output
    Copy
    1
    
    input
    Copy
    4 2
    abab
    
    output
    Copy
    0
    
    Note

    In the first example, we can select 22 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 22.

    In the second example, we can select either substring "a" or "b" to get the answer 11.

    题意概括:

    给一串长度为 N 的字符,求长度为 K 的由相同单种字母组成的子串的最大数量。

    解题思路:

    单指针模拟长度为 K 的子串的起始点,O(N)遍历一遍整个字符,记录每种字母满足条件的子串所对应的数量。

    AC code:

     1 #include <bits/stdc++.h>
     2 #define INF 0x3f3f3f3f
     3 #define LL long long
     4 using namespace std;
     5 const int MAXN = 2e5+10;
     6 char str[MAXN];
     7 int num[30];
     8 int main()
     9 {
    10     int N, K;
    11     scanf("%d %d", &N, &K);
    12     scanf("%s", str);
    13     int len = strlen(str);
    14     int st = 0;
    15     bool flag;
    16     while(st+K-1 < len){
    17         flag = true;
    18         for(int i = st+1; i <= st+K-1; i++){
    19             //printf("%c %c
    ", str[i], str[i-1]);
    20             if(str[i] != str[i-1]){
    21                 flag = false;
    22                 st = i;
    23                 break;
    24             }
    25         }
    26         if(flag){
    27             //printf("%d %c
    ",st, str[st]);
    28             num[str[st]-'a']++;
    29             st = st+K;
    30         }
    31         //st+=K;
    32     }
    33     int ans = 0;
    34     for(int i = 0; i < 26; i++){
    35         //printf("%d %d
    ", i, num[i]);
    36         ans = max(num[i], ans);
    37     }
    38 
    39     printf("%d
    ", ans);
    40     return 0;
    41 
    42 }
  • 相关阅读:
    POJ2976 Dropping tests 01分数规划
    POJ 2728 Desert King 01分数规划,最优比率生成树
    codeforces 675E Trains and Statistic 线段树+贪心统计
    codeforces 675D Tree Construction set
    UVA 11235Frequent values(RMQ)
    FZU 2105Digits Count(线段树 + 成段更新)
    HDU 4006The kth great number(K大数 +小顶堆)
    UVA 624CD(01背包输出 + 输出路径)
    HDU 1796How many integers can you find(容斥原理)
    HDU 1817Necklace of Beads(置换+Polya计数)
  • 原文地址:https://www.cnblogs.com/ymzjj/p/10300631.html
Copyright © 2011-2022 走看看