Homework （BNUOJ 5134）

題目鏈接

簡單的字符串處理

#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <string>
#include <cmath>
#include <queue>
#include <set>
#include <fstream>
using namespace std;
char str[100005];
int cnt[26], tmp[26];
int vis[26];
int main()
{
    int k;
    while(cin >> str){
    cin >> k;
    int i, len = strlen(str);
    memset(cnt, 0, sizeof(cnt));
    memset(vis, 0, sizeof(vis));
    memset(tmp, 0, sizeof(tmp));
    if(k >= len)
    {
        cout << 0 << endl << endl;
    }
    else
    {

        for(i = 0; i < len; i++)
        {
            cnt[str[i]-'a']++;
            tmp[str[i]-'a']++;
        }
        sort(cnt, cnt+26);
        int j;
        for(i = 0; i < 26; i++)
        {
            if(cnt[i] == 0)
                continue;
            if(cnt[i] <= k)
            {
                k -= cnt[i];
                for(j = 0; j < 26; j++)
                {
                    if(tmp[j] == cnt[i] && !vis[j])
                    {
                        vis[j] = 1;
                        break;
                    }
                }
            }
            else
            {
                cout << 26-i << endl;
                break;
            }
        }

        for(i = 0; i < len; i++)
        {
            if(vis[str[i]-'a'] == 1)
                continue;
            cout << str[i];
        }
        cout << endl;
    }
    }
    return 0;
}