Time: 273 ms (80.64%), Space: 97.1 MB (19.16%) - LeetHub

0380-insert-delete-getrandom-o1/0380-insert-delete-getrandom-o1.cpp

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+class RandomizedSet {
+public:
+    vector<int> vec;
+    unordered_map<int,int> mp;
+    RandomizedSet() {
+
+    }
+
+    bool insert(int val) {
+        if(mp.find(val)!=mp.end())
+        {
+            return false;
+        }
+        vec.push_back(val);
+        mp[val]=vec.size()-1;
+        return true;
+
+    }
+
+    bool remove(int val) {
+        if(mp.find(val)!=mp.end())
+        {
+            int ind=mp[val];
+            int last=vec.back();
+            vec.back()=val;
+            vec[ind]=last;
+            mp[last]=ind;
+            vec.pop_back();
+            mp.erase(val);
+            return true;
+
+
+        }
+        return false;
+
+
+
+    }
+
+    int getRandom() {
+        int n=vec.size();
+        int num=rand()%n;
+        return vec[num];
+
+    }
+};
+
+/**
+ * Your RandomizedSet object will be instantiated and called as such:
+ * RandomizedSet* obj = new RandomizedSet();
+ * bool param_1 = obj->insert(val);
+ * bool param_2 = obj->remove(val);
+ * int param_3 = obj->getRandom();
+ */