[usth/MATH2.3] Mathemate Discretely

1 files changed, 43 insertions, 0 deletions

diff --git a/usth/MATH2.3/3/dc.cc b/usth/MATH2.3/3/dc.cc
new file mode 100644
index 0000000..b69742a
--- /dev/null
+++ b/usth/MATH2.3/3/dc.cc
@@ -0,0 +1,43 @@
+#include <cmath>
+#include <iostream>
+#include <sstream>
+#include <string>
+#include <vector>
+
+using namespace std;
+
+int
+main ()
+{
+  double num, x, y;
+  string op;
+  vector<double> v;
+
+  while (cin.peek () != '\n')
+    {
+      getline (cin, op, ';');
+      stringstream s {op};
+      s >> num;
+      if (s)
+        {
+          v.push_back (num);
+          continue;
+        }
+
+      y = v.back ();
+      v.pop_back ();
+      x = v.back ();
+      v.pop_back ();
+      if (op == "^")
+        v.push_back (pow (x, y));
+      else if (op == "+")
+        v.push_back (x + y);
+      else if (op == "-")
+        v.push_back (x - y);
+      else if (op == "*")
+        v.push_back (x * y);
+      else if (op == "/")
+        v.push_back (x / y);
+    }
+  cout << v.back () << endl;
+}