Cod sursa(job #2505137)

Utilizator Tudor_1808Tudor Ioan Popescu Tudor_1808 Data 6 decembrie 2019 11:35:54
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.06 kb
#include <iostream>
#include <fstream>

using namespace std;

ifstream in("evaluare.in");
ofstream out("evaluare.out");

const int N = 1000001;
int p;
char s[N];
int expresie();
int termen();
int factor();

int expresie(){
    int sum=termen();
    while(s[p]=='+' || s[p]=='-'){
        if(s[p]=='+'){
            p++;
            sum+=termen();
        }
        if(s[p]=='-'){
            p++;
            sum-=termen();
        }
    }
    return sum;
}

int termen(){
    int prod=factor();
    while(s[p]=='*' || s[p]=='/'){
        if(s[p]=='*'){
            p++;
            prod*=factor();
        }
        if(s[p]=='/'){
            p++;
            prod/=factor();
        }
    }
    return prod;
}

int factor(){
    int val=0, semn=1;
    while(s[p]=='-'){
        p++;
        semn=-semn;
    }
    if(s[p]=='('){
        p++;
        val=expresie();
        p++;
        return semn*val;
    }
    while(s[p]>='0' && s[p]<='9'){
        val=val*10+(s[p]-'0');
        p++;
    }
    return semn*val;
}

int main()
{
    in>>s;
    out<<expresie();

    return 0;
}