Cod sursa(job #2734534)

Utilizator enedumitruene dumitru enedumitru Data 1 aprilie 2021 06:26:37
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.11 kb
#include <fstream>
using namespace std;
ifstream f("evaluare.in"); ofstream g("evaluare.out");
char s[100001],st1[100001];
int nr,k1,k2,st2[100001],pr[300];
void operatie()
{   switch(st1[k1])
    {   case '+' : st2[k2-1]+=st2[k2]; break;
        case '-' : st2[k2-1]-=st2[k2]; break;
        case '*' : st2[k2-1]*=st2[k2]; break;
        case '/' : st2[k2-1]/=st2[k2]; break;
    }
    k2--; k1--;
}
int main()
{   f>>s;
    pr['(']=pr[')']=0;
    pr['+']=pr['-']=1;
    pr['*']=pr['/']=2;
    for(int i=0;s[i]!=0;i++)
    {   if('0'<=s[i] && s[i]<='9')
        {   nr=0;
            while('0'<=s[i] && s[i]<='9') {nr=nr*10+s[i]-'0'; i++;}
            i--;
            st2[++k2]=nr;
        }
        else if(s[i] == '(') st1[++k1] = '(';
            else if(s[i]==')')
                {   while(st1[k1]!='(') operatie();
                    k1--;
                }
                else
                {   while(k1 && pr[st1[k1]]>=pr[s[i]]) operatie();
                    st1[++k1] = s[i];
                }
    }
    while(k1) operatie();

    g<<st2[1]; g.close(); f.close(); return 0;
}