Pagini recente » Cod sursa (job #1326727) | Cod sursa (job #439050) | Cod sursa (job #1871429) | Cod sursa (job #196493) | Cod sursa (job #1987268)
#include <iostream>
#include <fstream>
#include <cstdlib>
#include <stack>
#include <cstring>
using namespace std;
ifstream in("evaluare.in");
ofstream out("evaluare.out");
#define ll long long
#define pb push_back
const int strMax = 1e5 + 5;
const ll inf = 9e18 + 5;
int N,nrPost;
int prio[(1<<8) + 5];
char str[strMax];
struct elem {
int nr;
char op;
elem(int _nr = 0,char _op = '\0') {
nr = _nr;
op = _op;
}
}post[strMax];
int main() {
in>>(str+1);
str[0] = '(';
str[N = strlen(str)] = ')';
++N;
prio['('] = 1;
prio[')'] = prio['+'] = prio['-'] = 2;
prio['*'] = prio['/'] = 3;
stack<char> ops;
for (int i=0;i < N;++i) {
if (str[i] == '(') {
ops.push('(');
}
else if ('0' <= str[i] && str[i] <= '9') {
int nr = 0;
while ('0' <= str[i] && str[i] <= '9') {
nr = nr * 10 + str[i++]-'0';
}
--i;
post[++nrPost] = elem(nr);
}
else {
while (prio[ops.top()] >= prio[str[i]]) {
post[++nrPost] = elem(0,ops.top());
ops.pop();
}
if (str[i] == ')') {
ops.pop();
}
else {
ops.push(str[i]);
}
}
}
stack<int> num;
for (int i=1;i <= nrPost;++i) {
if (post[i].op == '\0') {
num.push(post[i].nr);
}
else {
int nr1,nr2,ans;
nr1 = num.top(); num.pop();
nr2 = num.top(); num.pop();
char op = post[i].op;
switch (op) {
case '+': ans = nr2+nr1; break;
case '-': ans = nr2-nr1; break;
case '*': ans = nr2*nr1; break;
case '/': ans = nr2/nr1; break;
}
num.push(ans);
}
}
out<<num.top()<<'\n';
in.close();out.close();
return 0;
}