zoukankan      html  css  js  c++  java
  • CF999C Alphabetic Removals 思维 第六道 水题

    Alphabetic Removals
    time limit per test
    2 seconds
    memory limit per test
    256 megabytes
    input
    standard input
    output
    standard output

    You are given a string ss consisting of nn lowercase Latin letters. Polycarp wants to remove exactly kk characters (knk≤n) from the string ss. Polycarp uses the following algorithm kk times:

    • if there is at least one letter 'a', remove the leftmost occurrence and stop the algorithm, otherwise go to next item;
    • if there is at least one letter 'b', remove the leftmost occurrence and stop the algorithm, otherwise go to next item;
    • ...
    • remove the leftmost occurrence of the letter 'z' and stop the algorithm.

    This algorithm removes a single letter from the string. Polycarp performs this algorithm exactly kk times, thus removing exactly kkcharacters.

    Help Polycarp find the resulting string.

    Input

    The first line of input contains two integers nn and kk (1kn41051≤k≤n≤4⋅105) — the length of the string and the number of letters Polycarp will remove.

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

    Output

    Print the string that will be obtained from ss after Polycarp removes exactly kk letters using the above algorithm kk times.

    If the resulting string is empty, print nothing. It is allowed to print nothing or an empty line (line break).

    Examples
    input
    Copy
    15 3
    cccaabababaccbc
    output
    Copy
    cccbbabaccbc
    input
    Copy
    15 9
    cccaabababaccbc
    output
    Copy
    cccccc
    input
    Copy
    1 1
    u
    output
    Copy
    
    

    这三天写CF终于一遍过了一道题

    题意: 给你n个字符,让你删除k个字符,从a开始删,从左到右,删完k个为止,全部删完输出“nothing”或者不输出

    vis数组记录每个字符的个数,然后计算下删k个字符删到那个字符为止,记录下剩余这个字符的数量,将这个字符前面的字符的记录值归0

    然后从后往前遍历,遇到vis数组还有值得就加入保存结果得字符串t

    最后反着输出字符串t(因为你开始时从后往前遍历的,得到的是倒的字符串)

    #include <map>
    #include <set>
    #include <cmath>
    #include <queue>
    #include <cstdio>
    #include <vector>
    #include <string>
    #include <cstring>
    #include <iostream>
    #include <algorithm>
    #define debug(a) cout << #a << " " << a << endl
    using namespace std;
    const int maxn = 1e6 + 10;
    const int mod = 1e9 + 7;
    typedef long long ll;
    int main(){
        std::ios::sync_with_stdio(false);
        ll n, k;
        while( cin >> n >> k ) {
            string s;
            cin >> s;
            ll vis[50] = {0}, num = 0;
            for( ll i = 0; i < s.length(); i ++ ) {
                vis[s[i]-'a'] ++;
            }
            for( ll i = 0; i <= 25; i ++ ) {
                num += vis[i];
                if( num > k ) {
                    vis[i] = vis[i] - ( k - ( num - vis[i] ) );
                    break;
                } else {
                    vis[i] = 0;
                }
            }
            string t = "";
            for( ll i = s.length()-1; i >= 0; i -- ) {
                if( vis[s[i]-'a'] ) {
                    t += s[i];
                    vis[s[i]-'a'] --;
                }
            }
            if( t.length() == 0 ) {
                cout << endl;
                continue;
            }
            for( ll i = t.length()-1; i >= 0; i -- ) {
                cout << t[i];
            }
            cout << endl;
        }
        return 0;
    }
    彼时当年少,莫负好时光。
  • 相关阅读:
    Silver Cow Party
    vue+cli3多页面配置(附带axios拦截器)以及链接跳转传参
    jsp根据表单填写内容追加生成json
    Mobiscroll插件-根据时间选择弹出星座
    javascript sdk – 如何注销我使用OAuth2通过Google登录的应用程序?
    解决React Native安装应用到真机(红米3S)报Execution failed for task ':app:installDebug'的错误
    解决React Native安装应用到真机(红米手机)报Execution failed for task ':app:installDebug'的错误
    windows RN 环境搭建(实测心得)
    windows RN 环境搭建(实测心得)
    facebook 推特. Line 领英 分享功能 带图标(最全,实测可用)
  • 原文地址:https://www.cnblogs.com/l609929321/p/9215179.html
Copyright © 2011-2022 走看看