Create 0155-min-stack.dart

Author: ishworpanta10

dart/0155-min-stack.dart

@@ -0,0 +1,28 @@
+class MinStack {
+  final List<int> stack = [];
+  final List<int> minStack = [];
+
+  MinStack();
+
+  void push(int val) {
+    stack.add(val);
+    if (minStack.isEmpty) {
+      minStack.add(val);
+    } else {
+      minStack.add(min(val, minStack.last));
+    }
+  }
+
+  void pop() {
+    stack.removeLast();
+    minStack.removeLast();
+  }
+
+  int top() {
+    return stack.last;
+  }
+
+  int getMin() {
+    return minStack.last;
+  }
+}