字符统计

Posted 2022-08-11 wuyi_all_in

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#include<iostream>
#include<string>
#include<vector>
using namespace std;
int main()
 
    string str;
    while(cin>>str)
    
        vector<int>count(256,0);
        int max=0;
        for(int i=0;i<str.size();i++)
        
            count[str[i]]++;
            if(count[str[i]]>max)
            
                //遍历完一次之后，max就是当前字符中出现的次数最多的
                max=count[str[i]];
            
        
        while(max)
        
            for(int i=0;i<256;i++)
            
                //从头到尾依次遍历，依次打印出数量为max的字符，解决了数量大小一致按照ASII码从小到大排序输出
                if(count[i]==max)
                
                    printf("%c",i);
                
            
            max--;
        
        printf("\\n");
    
    return 0;

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 错误代码，有待改善

#include<iostream>
#include<string>
#include<map>
#include<queue>
#include<functional>
using namespace std;
bool mycmp(pair<int,char>a,pair<int,char>b)

    if(a.first>b.first)
        return false;
    else if(a.first==b.first)
    
        if(a.second<b.second)return false;
        else return true;
    
    else return true;

int main()

    map<char,int>record_1;
    string str;
    priority_queue<pair<int,char>,vector<pair<int,char>>,function<bool(pair<int,char>,pair<int,char>)>>record_2(mycmp);
    //priority_queue<pair<int,char>>record_2;
    while(cin>>str)
    
        cout<<str.size();
        for(char a:str)
            record_1[a]++;
        for(auto b:record_1)
            record_2.push(b.second,b.first);
        pair<int,char>used=0,0;
        while(record_2.size()!=0)
        
            auto res=record_2.top();
            cout<<res.second;
            record_2.pop();
        
        cout<<endl;
    

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