Cod sursa(job #1132665)

Utilizator Cosmin1490Balan Radu Cosmin Cosmin1490 Data 3 martie 2014 19:44:01
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 2.22 kb
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <fstream>
#include <iterator>
#include <random>
#include <assert.h>
using namespace std;

const string file = "evaluare";

const string infile = file + ".in";
const string outfile = file + ".out";

const int INF = 0x3f3f3f3f; 

//#define ONLINE_JUDGE

int expresie(string& A, int& i, int N);
int termen(string& A, int& i, int N);
int factor(string& A, int& i, int N);

int expresie(string& A, int& i, int N)
{
   int t = termen(A, i, N); 
   while(i < N && (A[i] == '+' || A[i] == '-'))
   {
       int j = i;
       i++;
       int c = termen(A, i, N);
       if(A[j] == '+')
       {
           t += c;
       }
       else//(A[j] == '-')
       {
           t -= c;
       }
   }
   return t;
}

int termen(string& A, int& i, int N)
{
    int f = factor(A, i, N);
    while(i < N && (A[i] == '*' || A[i] == '/'))
    {
        int j = i;
        i++;
        int c = factor(A, i, N);
        if(A[j] == '*')
        {
            f *= c;
        }
        else//if(A[j] == '/')
        {
            f /= c;
        }
    }
    return f;
}

int factor(string& A, int& i, int N)
{
    int e = 0;
    if(A[i] == '(')
    {
       i++;
       e = expresie(A, i, N);
       i++;
    }
    else
    {
        while(i < N && '0' <= A[i] && A[i] <= '9')
        {
            e *= 10;
            e += A[i] - '0';
            i++;
        }
    }
    return e;
}


int main()
{
#ifdef ONLINE_JUDGE
	ostream &fout = cout;
	istream &fin = cin;
#else
	fstream fin(infile.c_str(), ios::in);
	fstream fout(outfile.c_str(), ios::out);
#endif	

    string A;
    fin >> A;
    int i = 0;
    fout << expresie(A, i, A.length());
#ifdef ONLINE_JUDGE
#else
    fout.close();
	fin.close();
#endif
}