Create 155.min-stack.cpp

Author: rachitiitr

LeetCode/155.min-stack.cpp

@@ -0,0 +1,39 @@
+class MinStack {
+public:
+    /** initialize your data structure here. */
+    vector<int> a, b;
+    MinStack() {
+        a = b = {};
+    }
+    
+    void push(int x) {
+        a.push_back(x);
+        if(b.empty()) b.push_back(x);
+        else {
+            int newMin = min(x, *b.rbegin());
+            b.push_back(newMin);
+        }
+    }
+    
+    void pop() {
+        a.pop_back();
+        b.pop_back();
+    }
+    
+    int top() {
+        return *a.rbegin();
+    }
+    
+    int getMin() {
+       return *b.rbegin();
+    }
+};
+
+/**
+ * Your MinStack object will be instantiated and called as such:
+ * MinStack* obj = new MinStack();
+ * obj->push(x);
+ * obj->pop();
+ * int param_3 = obj->top();
+ * int param_4 = obj->getMin();
+ */