老是超时有办法解决，或者更简单的方法

输入
i have brought #peace #freedom #justice and #security to my new empire
输出
4
#freedom 1
#justice 1
#peace 1
#security 1
代码：

#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
using std::cin;
using std::cout;
using std::vector;
using std::string;
using std::find;
class Solution{
public:
    static vector<string> tags(vector<string> inputs){
        vector<string> tag;
        for(string x:inputs){
            if(x[0]=='#'&&x.size()>1&&x.find('#',1)==x.npos){
                tag.push_back(x);
            }
        }
        return tag;
    }
    static int tag_num(vector<string>tag){
        int num=0;
        int flag=0;
        for(string x:tag){
            if(count(tag.begin()+flag, tag.end(), x)<=1){
                num++;
            }
            flag++;
        }
        return num;
    }
    static int single(string x,vector<string>tag){
        int num=0;
        for(string y:tag){
            if(x.compare(y)==0){
                num++;
            }
        }
        return num;
    }
};
int main(int argc, char const *argv[])
{
    string str;
    vector<string> orn;
   
    while(cin>>str){
        orn.push_back(str);
    }
    vector<string> tags(Solution::tags(orn));
    cout<<Solution::tag_num(tags)<<std::endl;
    vector<string> tags_new(tags);
    sort( tags_new.begin(), tags_new.end() );
    tags_new.erase( unique( tags_new.begin(), tags_new.end() ), tags_new.end() );
    for(auto x:tags_new){
        cout<<x<<" "<<Solution::single(x,tags)<<std::endl;
    }
    return 0;
}

题目如下：

#include<iostream>
#include<unordered_map>
#include<string>
#include<sstream>
#include<algorithm>
using namespace std;
int main()
{
    string line;
    unordered_map<string, int> tags;
    getline(cin, line);
    int i = 0;
    string word = "";
    stringstream stream(line);
    while (stream >> word)
        if (word.size() > 1 && word[0] == '#' && count(word.begin(), word.end(), '#') == 1)tags[word]++;
    cout << tags.size() << endl;
    for (const auto tag : tags)
        cout << tag.first << " " << tag.second << endl;
}

记录标签起始位置和结束位置就行

#include<stdio.h>
#include<string.h>
char t[100000];
int b[100000];
int e[100000];
int bp=0,ep=0;
int count[100000];
char lable[100000][150];
int p=0;
int main()
{
    gets(t);
    int len=strlen(t);
    for(int i=0; i<len; i++)
    {
        if(t[i]=='#')
        {
            b[bp++]=i;
            for(int j=i; j<=len; j++)
            {
                if(t[j]==' '||j==len)
                {
                    e[ep++]=j;
                    break;
                }
            }
        }
    }
    for(int i=0; i<bp; i++)
    {
        p=0;
        for(int j=b[i]; j<e[i]; j++)
        {
            lable[i][p++]=t[j];
        }
        lable[i][p]='\0';
    }
    for(int i=0; i<bp; i++)
    {
        for(int j=0; j<bp; j++)
        {
            if(strcmp(lable[i],lable[j])==0&&i!=j)
            {
                count[i]++;
                lable[j][0]='\0';
            }
        }
    }
    printf("%d\n",bp);
    /*for(int i=0; i<bp; i++)
    {
        for(int j=b[i]; j<=e[i]; j++)
        {
            printf("%c",t[j]);
        }
        printf("%d",count[i]);
        printf("\n");
    }*/
    for(int i=0; i<bp; i++)
    {
        if(lable[i][0]!='\0')
        {
            printf("%s",lable[i]);
            printf(" %d\n",count[i]+1);
        }
    }
    return 0;
}

#include <iostream>
#include <vector>
#include <unordered_map>
using namespace std;
unordered_map<string,int> func(string str){
    unordered_map<string, int> res;
    string word;
    int len = str.length();
    for (int i = 0; i < len; i++)
    {
        if (str[i] == ' ')
        {
            if (word.length() == 0)
                continue;
            else if(word[0]=='#'){
                res[word]++;
                word = "";
            }
            else {
                word = "";
            }
        }
        else {
            word += str[i];
        }
    }
    return res;
}

int main()
{
    string str = "i have brought #peace #peace  #freedom #justice and #security to my new empire";
    auto ans = func(str);
    cout << ans.size() << endl;
    for (auto x : ans) {
        cout << x.first << " " << x.second << endl;
    }
    
}

#include <algorithm>
#include <iostream>
#include <iterator>
#include <map>
#include <string>
#include <vector>

int main()
{
    std::vector<std::string> tokens;
    std::copy_if(std::istream_iterator<std::string>(std::cin), 
                 std::istream_iterator<std::string>(), 
                 std::back_inserter(tokens), 
                 [](const auto& token) 
                 { return token.length() > 1 
                       && std::count(token.begin(), token.end(), '#') == 1 
                       && token[0] == '#'; });

    std::map<std::string, int> statistics;
    std::for_each(tokens.begin(), tokens.end(), 
                  [&statistics](const auto& token) 
                  { statistics[token]++; });

    std::cout << statistics.size() << std::endl;
    std::for_each(statistics.begin(), statistics.end(), 
                  [](const auto& item) 
                  { std::cout << item.first << " " << item.second << std::endl; });
    
    return 0;
}