Cod sursa(job #2110000)

Utilizator bogfodorBogdan Fodor bogfodor Data 20 ianuarie 2018 11:59:36
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.21 kb
#include <iostream>
#include <fstream>
#include <string.h>

using namespace std;

char s[100005];

int cautas(int st, int dr, char s1, char s2)
{
    int nr=0;
    for(int i=dr;i>=st;i--)
    {
        if(s[i]==')')
            nr++;
        if(s[i]=='(')
            nr--;
        if(nr==0 && (s1==s[i] || s2==s[i]))
            return i;
    }
     return -1;
}

int num(int st, int dr)
{
    int numar=0;
    for(int i=st;i<=dr;i++)
        numar=numar*10+(s[i]-'0');
    return numar;
}

int solve(int st, int dr)
{
    int poz=cautas(st,dr,'+','-');
    if(poz!=-1)
    {
        int e1=solve(st,poz-1);
        int e2=solve(poz+1,dr);
        if(s[poz]=='+')
            return e1+e2;
        return e1-e2;
    }
    poz=cautas(st,dr,'*','/');
    if(poz!=-1)
    {
        int e1=solve(st,poz-1);
        int e2=solve(poz+1,dr);
        if(s[poz]=='*')
            return e1*e2;
        return e1/e2;
    }
    if(s[st]=='(' && s[dr]==')')
        return solve(st+1,dr-1);
    return num(st,dr);
}

int main()
{
    ifstream fin("evaluare.in");
    ofstream fout("evaluare.out");
    fin.getline(s,100005);
    int n=strlen(s);
    fout<<solve(0,n-1);
    return 0;
}