Cod sursa(job #1317895)
Utilizator | Data | 15 ianuarie 2015 12:49:38 | |
---|---|---|---|
Problema | Evaluarea unei expresii | Scor | 10 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 2.05 kb |
#include <iostream>
#include <fstream>
#include <string.h>
using namespace std;
ifstream fin("evaluare.in");
ofstream fout("evaluare.out");
int n,i,nr,OK,od[100001],vr,vf;
char s[100001],pr[126],op[100001];
int calcul(char ch,int a,int b)
{
if (ch=='+')
return a+b;
if (ch=='-')
return a-b;
if (ch=='*')
return a*b;
if (ch=='/')
return a/b;
}
int main()
{
fin >>s+1;
n=strlen(s+1);
pr['+']=pr['-']=1;
pr['*']=pr['/']=2;
for(i=1;i<=n;i++)
{
if(s[i]>='0'&&s[i]<='9')
{
OK=1;
nr=nr*10+(s[i]-'0');
}
else
{
if(s[i]=='(')
{
if(OK==1)
{
od[++vr]=nr;
nr=0;OK=0;
}
op[++vf]=s[i];
}
else
if(s[i]==')')
{
if(OK==1)
{
od[++vr]=nr;
nr=0;OK=0;
}
while (op[vf]!='(')
{
od[vr-1]=calcul(op[vf],od[vr-1],od[vr]);
vf--;
vr--;
}
vf--;
}
else
{
if(OK==1)
{
od[++vr]=nr;
nr=0;OK=0;
}
if(vf>0&&pr[s[i]]<=pr[op[vf]])
{
od[vr-1]=calcul(op[vf],od[vr-1],od[vr]);
vr--;
}
op[++vf]=s[i];
}
}
}
while(vf>0)
{
if(OK==1)
{
od[++vr]=nr;
nr=0;OK=0;
}
od[vr-1]=calcul(op[vf],od[vr-1],od[vr]);
vf--;
vr--;
}
fout<<od[1];
return 0;
}