Create design-browser-history.cpp

Author: kamyu104

C++/design-browser-history.cpp

@@ -0,0 +1,33 @@
+// Time:  ctor  : O(1)
+//        visit : O(1)
+//        back  : O(1)
+//        foward: O(1)
+// Space: O(n)
+
+class BrowserHistory {
+public:
+    BrowserHistory(string homepage)
+      : history_(1, homepage)
+      , curr_{0} {
+        
+    }
+    
+    void visit(string url) {
+        history_.resize(++curr_);
+        history_.emplace_back(url);
+    }
+    
+    string back(int steps) {
+        curr_ = max(curr_ - steps, 0);
+        return history_[curr_];
+    }
+    
+    string forward(int steps) {
+        curr_ = min(curr_ + steps, int(history_.size()) - 1);
+        return history_[curr_];
+    }
+
+private:
+    vector<string> history_;
+    int curr_;
+};