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  1.  
  2.  
  3. // Saif Khan - 21/03/2017
  4.  
  5. #include <bits/stdc++.h>
  6.  
  7. using namespace std;
  8.  
  9. #define rd freopen("in.txt", "r", stdin)
  10. #define wr freopen("out.txt", "w", stdout)
  11. #define ios ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
  12. #define mset(x, v) memset(x, v, sizeof(x))
  13. #define FOR(n) for (int i = 0; i < n; i++)
  14.  
  15. using namespace std;
  16.  
  17. vector<string> split(string s) {
  18.   string tnum = "";
  19.   vector<string> v;
  20.   for (int i = 0; i < s.size(); i++) {
  21.     if (s[i] >= '0' && s[i] <= '9') {
  22.       tnum += s[i];
  23.     } else {
  24.       if (tnum != "") {
  25.         if (v.back() == "-" && v.size() - 2 >= 0 && v[v.size() - 2] == "(") {
  26.           v.pop_back();
  27.           tnum = "-" + tnum;
  28.         }
  29.         v.push_back(tnum);
  30.         tnum = "";
  31.       }
  32.       string ts = "";
  33.       ts += s[i];
  34.       v.push_back(ts);
  35.     }
  36.   }
  37.   return v;
  38. }
  39.  
  40. bool check(string s) { return s == "+" || s == "-" || s == "*" || s == "/"; }
  41.  
  42. bool checkPriority(string a, string b) {
  43.   int aa = -1;
  44.   int bb = -1;
  45.   if (a == "+" || a == "-")
  46.     aa = 1;
  47.   else if (a == "*" || a == "/")
  48.     aa = 2;
  49.   if (b == "+" || b == "-")
  50.     bb = 1;
  51.   else if (b == "*" || b == "/")
  52.     bb = 2;
  53.   return aa >= bb;
  54. }
  55.  
  56. vector<string> infixToPostfix(vector<string> v) {
  57.   stack<string> st;
  58.   vector<string> postfix;
  59.   for (int i = 0; i < v.size(); i++) {
  60.     if (check(v[i])) {
  61.       while (!st.empty() && st.top() != "(" && checkPriority(st.top(), v[i])) {
  62.         postfix.push_back(st.top());
  63.         st.pop();
  64.       }
  65.       st.push(v[i]);
  66.     } else if (v[i] == "(") {
  67.       st.push(v[i]);
  68.     } else if (v[i] == ")") {
  69.       while (!st.empty() && st.top() != "(") {
  70.         postfix.push_back(st.top());
  71.         st.pop();
  72.       }
  73.       st.pop();
  74.     } else {
  75.       postfix.push_back(v[i]);
  76.     }
  77.   }
  78.   while (!st.empty()) {
  79.     postfix.push_back(st.top());
  80.     st.pop();
  81.   }
  82.   return postfix;
  83. }
  84.  
  85. double mathOperation(double t1, double t2, string s) {
  86.   if (s == "*") return t2 * t1;
  87.   if (s == "/") return t2 / t1;
  88.   if (s == "+") return t2 + t1;
  89.   if (s == "-") return t2 - t1;
  90.   return 0;
  91. }
  92.  
  93. double toDouble(string s) {
  94.   stringstream ss;
  95.   ss << s;
  96.   double d;
  97.   ss >> d;
  98.   return d;
  99. }
  100.  
  101. string toString(double d) {
  102.   stringstream ss;
  103.   ss << d;
  104.   return ss.str();
  105. }
  106.  
  107. string postfixEvaluation(vector<string> v) {
  108.   stack<double> s;
  109.   double d;
  110.   for (int i = 0; i < v.size(); i++) {
  111.     if (check(v[i])) {
  112.       double d1 = s.top();
  113.       if (d1 == 0.0) {
  114.         return "Infinity";
  115.       }
  116.       s.pop();
  117.       double d2 = s.top();
  118.       s.pop();
  119.       d = mathOperation(d1, d2, v[i]);
  120.       s.push(d);
  121.     } else {
  122.       s.push(toDouble(v[i]));
  123.     }
  124.   }
  125.   return toString(d);
  126. }
  127.  
  128. string calculate(string s) {
  129.   vector<string> v;
  130.   v = split(s);
  131.   v = infixToPostfix(v);
  132.   s = postfixEvaluation(v);
  133.   return s;
  134. }
  135.  
  136. int main() {
  137.   ios;
  138.   int n;
  139.   cin >> n;
  140.   string s;
  141.   while (n--) {
  142.     cin >> s;
  143.     string sum = calculate(s);
  144.     if (sum != "Infinity") {
  145.       cout << fixed << setprecision(1) << toDouble(sum) << '\n';
  146.     } else {
  147.       cout << sum << '\n';
  148.     }
  149.   }
  150.   return 0;
  151. }
Success #stdin #stdout 0s 16080KB
comments (?)
stdin
copy 
8
(310+14)
(9-((-5)/2))
((123+(4*5))-7)
((9-((5/(8-3))*2))+6)
(5+(4/(2+(-2))))
((3+((3*(5+4))/2))-7)
((14-5)/(9-6))
((-6)+((7*2)/14))
stdout
copy 
324.0
11.5
136.0
13.0
Infinity
9.5
3.0
-5.0
https://ideone.com/afcopb
language:
C++ (gcc 8.3)
created:
7 years ago
visibility:
public

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