tasks a-s

Task/Parsing-RPN-calculator-algorithm/D/parsing-rpn-calculator-algorithm.d

@@ -0,0 +1,26 @@
+import std.stdio, std.string, std.conv, std.typetuple;
+
+void main() {
+    auto input = "3 4 2 * 1 5 - 2 3 ^ ^ / +";
+    writeln("For postfix expression: ", input);
+    writeln("\nToken            Action            Stack");
+    real[] stack;
+    foreach (tok; input.split()) {
+        auto action = "Apply op to top of stack";
+        switch (tok) {
+            foreach (o; TypeTuple!("+", "-", "*", "/", "^")) {
+                case o:
+                    mixin("stack[$ - 2]" ~
+                          (o == "^" ? "^^" : o) ~ "=stack[$ - 1];");
+                    stack.length--;
+                    break;
+            }
+            break;
+            default:
+                action = "Push num onto top of stack";
+                stack ~= to!real(tok);
+        }
+        writefln("%3s    %-26s  %s", tok, action, stack);
+    }
+    writeln("\nThe final value is ", stack[0]);
+}