Mai intai trebuie sa te autentifici.
Cod sursa(job #2526126)
Utilizator | Data | 18 ianuarie 2020 12:01:44 | |
---|---|---|---|
Problema | Evaluarea unei expresii | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 1.52 kb |
#include <bits/stdc++.h>
#define N 100001
using namespace std;
ifstream fin("evaluare.in");
ofstream fout("evaluare.out");
char s[N];
int evaluate(char*& expr);
int operand(char*& expr);
int value(char*& expr);
int plus_minus(char*& expr);
int ori_div(char*& expr);
int main(){
fin.get(s, N-1);
char* expr = s;
fout<<evaluate(expr);
return 0;
}
int evaluate(char*& expr)
{
return plus_minus(expr);
}
int operand(char*& expr)
{
int result;
if(expr[0] == '('){
result = evaluate(++expr);
++expr;
} else {
result = value(expr);
}
return result;
}
int value(char*& expr)
{
int result = 0;
while(isdigit(expr[0])){
result = result * 10 + (expr[0] - '0');
++expr;
}
return result;
}
int plus_minus(char*& expr)
{
int result = ori_div(expr);
while(expr[0] == '+' || expr[0] == '-'){
switch(expr[0]){
case '+':
result += ori_div(++expr);
break;
case '-':
result -= ori_div(++expr);
break;
}
}
return result;
}
int ori_div(char*& expr)
{
int result = operand(expr);
while(expr[0] == '*' || expr[0] == '/'){
switch(expr[0]){
case '*':
result *= operand(++expr);
break;
case '/':
result /= operand(++expr);
break;
}
}
return result;
}