Merge pull request #2260 from ishworpanta10/patch-3

Create 0150-evaluate-reverse-polish-notation.dart

Author: Ykhan799

dart/0150-evaluate-reverse-polish-notation.dart

@@ -0,0 +1,28 @@
+class Solution {
+  int evalRPN(List<String> tokens) {
+    var stack = [];
+    for (var i = 0; i < tokens.length; i++) {
+    var char = tokens[i];
+    if (char == '+') {
+      var a = stack.removeLast();
+      var b = stack.removeLast();
+      stack.add(a + b);
+    } else if (char == '-') {
+      var a = stack.removeLast();
+      var b = stack.removeLast();
+      stack.add(b - a);
+    } else if (char == '*') {
+      var a = stack.removeLast();
+      var b = stack.removeLast();
+      stack.add(a * b);
+    } else if (char == '/') {
+      var a = stack.removeLast();
+      var b = stack.removeLast();
+      stack.add(b ~/ a);
+    } else {
+      stack.add(int.parse(char));
+    }
+  }
+  return stack.first;
+  }
+}