CCF日常学习更新

由于我也是在学习，所以代码可能有些繁冗，希望能一起学习

AC代码

#include<bits/stdc++.h>
using namespace std;
int Str2N(string S)
{
    int i,sum=0;
    for(i=0;i<S.length();i++)
    {
        sum=10*sum+S[i]-'0';
    }
    return sum;
}
void Get(string element,map<string,int> &M,int K)
{
    int idn,idx,idy,idz,K0,K1,count;
    string ele,s;
    map<string,int>::iterator iter;
    //处理括号
    idn=0;
    while(element.find("(",idn)!=element.npos)
    {
        //括号
        idn=element.find("(",idn);
        //另一个括号
        for(idx=idn,count=0;idx<element.length();idx++)
        {
            if(element[idx]=='(')count++;
            if(element[idx]==')')count--;
            if(count==0)break;
        }
        //括号后面
        idy=idx+1;
        if(idy<element.length())
            while(element[idy]>='0'&&element[idy]<='9')idy++;
        if(idy>idx+1)
        {
            s=element.substr(idx+1,idy-idx-1);
            K0=Str2N(s);
        }
        else K0=1;
        s=element.substr(idn+1,idx-idn-1);
        Get(s,M,K*K0);
        element.erase(idn,idy-idn);
    }
    //处理完括号
    idn=-1;
    while(element.find_first_of("ABCDEFGHIJKLMNOPQRSTUVWXYZ",idn+1)!=element.npos)
    {
        //无括号元素
        idx=element.find_first_of("ABCDEFGHIJKLMNOPQRSTUVWXYZ",idn+1);
        idy=idx+1;
        while(element[idy]>='a'&&element[idy]<='z')idy++;
        ele=element.substr(idx,idy-idx);
        //后置系数K1
        idz=idy;
        if(idz<element.length())
            while(element[idz]>='0'&&element[idz]<='9')idz++;
        if(idz>idy)
        {
            s=element.substr(idy,idz-idy);
            K1=Str2N(s);
        }
        else K1=1;
        //存入元素
        if(M.find(ele)!=M.end())
        {  
            iter=M.find(ele);
            iter->second=iter->second+K*K1;
        }
        else
        {
            M.insert({ele,K*K1});
        }
        idn=idx;
    }
}
int main()
{
    int i,idn,idx,idy,flag,K,N;
    string str,element,s,s1,s2;
    map<string,int> left,right;
    map<string,int>::iterator iter,it;
    cin>>N;
    for(i=0;i<N;i++)
    {
        cin>>str;
        idn=str.find("=");
        s1=str.substr(0,idn);
        s2=str.substr(idn+1,str.length()-idn-1);
        s1=s1+"+";
        s2=s2+"+";
        idn=-1;
        while(s1.find("+",idn+1)!=s1.npos)
        {
            idx=s1.find_first_of("+",idn+1);
            element=s1.substr(idn+1,idx-idn-1);
            
            //提取系数K
            idn=element.find_first_of("0123456789");
            if(idn==0)
            {
                idy=element.find_first_not_of("0123456789");
                s=element.substr(idn,idy-idn);
                K=Str2N(s);
                element.erase(0,idy);
            }
            else K=1;

            Get(element,left,K);
            idn=idx;
        }
        idn=-1;
        while(s2.find_first_of("+",idn+1)!=s2.npos)
        {
            idx=s2.find_first_of("+",idn+1);
            element=s2.substr(idn+1,idx-idn-1);

            //提取系数
            idn=element.find_first_of("0123456789");
            if(idn==0)
            {
                idy=element.find_first_not_of("0123456789");
                s=element.substr(idn,idy-idn);
                K=Str2N(s);
                element.erase(0,idy);
            }
            else K=1;

            Get(element,right,K);
            idn=idx;
        }
        for(iter=left.begin(),flag=1;iter!=left.end();iter++)
        {
            it=right.find(iter->first);
            if(it==right.end()||iter->second!=it->second)flag=0;
        }
        if(left.size()!=right.size())flag=0;
        left.clear();
        right.clear();
        if(flag==0)cout<<"N"<<endl;
        else cout<<"Y"<<endl;
    }
    return 0;
}