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  1. #include <string>
  2. #include <iostream>
  3. #include <fstream>
  4. #include <sstream>
  5. #include <vector>
  6. #include <cmath>
  7. #include <algorithm>
  8.  
  9. //defines
  10. #define space ' '
  11.  
  12. //disables any deprecation warning
  13. #pragma warning(disable : 4996)
  14.  
  15. //usings
  16. using std::vector;
  17. using std::string;
  18. using std::cout;
  19. using std::endl;
  20.  
  21. long double nabs(long double dub) {
  22.     return -abs(dub);
  23. }
  24.  
  25. string remove_char(string str, char c = space) {
  26.     str.erase(std::remove(str.begin(), str.end(), c), str.end());
  27.     return str;
  28. }
  29.  
  30. long double parse(string str) {
  31.     return std::stold(str);
  32. }
  33.  
  34. bool try_parse(string str) {
  35.     char* end = 0;
  36.     long double val = strtold(str.c_str(), &end);
  37.     return end != str.c_str() && val != HUGE_VALL && val != -HUGE_VALL;
  38. }
  39.  
  40. char first_char(string str) {
  41.     return *str.c_str();
  42. }
  43.  
  44. bool is_opr(string str) {
  45.     return first_char(str) == '&';
  46. }
  47.  
  48. string &first_item(vector<string> vec) {
  49.     return vec[0];
  50. }
  51.  
  52. vector<string> get_types(vector<string> vec) {
  53.     for (int i = 0; i < vec.size(); i++) {
  54.         string &s = vec[i];
  55.         bool doubly = try_parse(s);
  56.         bool amp = is_opr(s);
  57.  
  58.         //if unknown
  59.         if (!doubly && !amp) {
  60.             s = "<unk> " + s;
  61.             continue;
  62.         }
  63.         //if operator
  64.         else if (!doubly && amp) {
  65.             s = "<opr> " + s;
  66.             continue;
  67.         }
  68.         //if number
  69.         else if (doubly && !amp) {
  70.             s = "<dub> " + s;
  71.             continue;
  72.         }
  73.  
  74.     }
  75.     return vec;
  76. }
  77.  
  78. long double interpretar_numero(string dub) {
  79.     if (dub.substr(0, 6).compare("<dub> ") != 0) {
  80.         throw "Não deu para interpretar como número " + dub;
  81.     }
  82.     return parse(dub.substr(6));
  83. }
  84.  
  85. long double get_result(vector<string> vec) {
  86.     if (vec.at(0).compare("<opr> &sb") == 0 || vec.at(0).compare("<opr> &ad") == 0) {
  87.         vec.insert(vec.begin(), "<dub> 0");
  88.     }
  89.     long double val = interpretar_numero(vec.at(0));
  90.     for (int i = 1; i < vec.size(); i += 2) {
  91.         std::string op = vec.at(i);
  92.         if (vec.size() == i + 1) throw "Esperava um número antes do fim";
  93.         long double ot = interpretar_numero(vec.at(i + 1));
  94.  
  95.         if (op.compare("<opr> &ad") == 0) {
  96.             val += ot;
  97.         } else if (op.compare("<opr> &sb") == 0) {
  98.             val -= ot;
  99.         } else if (op.compare("<opr> &mp") == 0) {
  100.             val *= ot;
  101.         } else if (op.compare("<opr> &dv") == 0) {
  102.             val /= ot;
  103.         } else {
  104.             throw "Esperava um operador";
  105.         }
  106.     }
  107.     return val;
  108. }
  109.  
  110. vector<string> split(string s, const char c = space) {
  111.     string buff{ "" };
  112.     vector<string> v;
  113.  
  114.     for (auto n : s) {
  115.         if (n != c) {
  116.             buff += n;
  117.         } else if (n == c && buff != "") {
  118.             v.push_back(buff);
  119.             buff = "";
  120.         }
  121.     }
  122.     if (buff != "") v.push_back(buff);
  123.  
  124.     return v;
  125. }
  126.  
  127. string simplify(string expr) {
  128.     string iexpr = expr;
  129.     for (int i = 0; i < iexpr.length(); i++) {
  130.  
  131.         char& c = iexpr[i];
  132.  
  133.         if (c == '+') {
  134.             iexpr.replace(i, 1, " &ad ");
  135.         } else if (c == '-') {
  136.             iexpr.replace(i, 1, " &sb ");
  137.         } else if (c == '*') {
  138.             iexpr.replace(i, 1, " &mp ");
  139.         } else if (c == '/') {
  140.             iexpr.replace(i, 1, " &dv ");
  141.         }
  142.     }
  143.     return iexpr;
  144. }
  145.  
  146. int main() {
  147.  
  148.     vector<string> sep_rep = get_types(split(simplify("-21 + 32 - 3 * 2")));
  149.     for (auto str : sep_rep) {
  150.         cout << str << endl;
  151.     }
  152.     try {
  153.         cout << "R: " << get_result(sep_rep) << endl;
  154.     } catch (const char *e) {
  155.         cout << "Erro: " << e;
  156.     } catch (string e) {
  157.         cout << "Erro: " << e;
  158.     }
  159.  
  160.     std::cin.get();
  161.     return 0;
  162. }
Success #stdin #stdout 0s 4540KB
comments (?)
stdin
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Standard input is empty
stdout
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<opr> &sb
<dub> 21
<opr> &ad
<dub> 32
<opr> &sb
<dub> 3
<opr> &mp
<dub> 2
R: 16
https://ideone.com/LXYDxV
language:
C++ (gcc 8.3)
created:
6 years ago
visibility:
public

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