Cod sursa(job #2632628)

Utilizator patcasrarespatcas rares danut patcasrares Data 4 iulie 2020 10:50:14
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.97 kb
#include<bits/stdc++.h>
using namespace std;
ifstream fin("evaluare.in");
ofstream fout("evaluare.out");
string s;
stack<char>sol;
stack<int>rez;
queue<string>q;
unordered_map<char,int>mp;
int me(char a,char b)
{
    return mp[a]>=mp[b];
}
int conv(string s)
{
    int ret=0;
    for(int i=0;i<s.size();i++)
        ret=ret*10+s[i]-'0';
    return ret;
}
int main()
{
    mp['+']=mp['-']=1;
    mp['*']=mp['/']=2;
    fin>>s;
    s='('+s+')';
    for(int i=0;i<s.size();i++)
    {
        if(s[i]=='(')
        {
            sol.push('(');
            continue;
        }

        if(s[i]==')')
        {
            while(sol.top()!='(')
            {
                string t;
                t+=sol.top();
                sol.pop();
                q.push(t);
            }
            sol.pop();
            continue;
        }

        if(isdigit(s[i]))
        {
            string t;
            while(isdigit(s[i]))
            {
                t+=s[i];
                i++;
            }
            i--;
            q.push(t);
            continue;
        }

        while(1)
        {
            if(sol.top()=='(')
                break;
            if(!me(sol.top(),s[i]))
                break;
            string t;
            //cout<<t<<'\n';
            t+=sol.top();
            sol.pop();
            q.push(t);
        }
        sol.push(s[i]);
    }
    while(!q.empty())
    {
        string t=q.front();
        q.pop();
        if(isdigit(t[0]))
        {
            //cout<<t<<' '<<conv(t)<<'\n';
            rez.push(conv(t));
            continue;
        }
        int g=rez.top();
        rez.pop();
        int f=rez.top();
        rez.pop();
        int z=0;
        if(t[0]=='+')
            z=f+g;
        if(t[0]=='-')
            z=f-g;
        if(t[0]=='*')
            z=f*g;
        if(t[0]=='/')
            z=f/g;
        rez.push(z);
    }
    fout<<rez.top()<<'\n';
}