155. Min Stack (using vector)

Author: SjxSubham

155. Min Stack

@@ -0,0 +1,34 @@
+class MinStack {
+public:
+    vector<pair<int,int>> st;        //we have make a vector
+    MinStack() {
+        
+    }
+    
+    void push(int val) {
+        if(st.empty()){
+            pair<int,int>p;// = make_pair(val,val);
+            p.first = val;
+            p.second = val;
+            st.push_back(p);
+        }
+        else{
+            pair<int,int>p;
+            p.first = val;
+            p.second = min(val, st.back().second);
+            st.push_back(p);
+        }
+    }
+    
+    void pop() {
+        st.pop_back();
+    }
+    
+    int top() {
+        return st.back().first;
+    }
+    
+    int getMin() {
+        return st.back().second;
+    }
+};