Create 0706-design-hashmap.cpp

cpp/0034-find-first-and-last-position-of-element-in-sorted-array.cpp

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+// Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value.
+
+// If target is not found in the array, return [-1, -1].
+
+// TC : O(log n) , SC : O(1)
+
+
+
+class Solution {
+
+    public:
+  int f(vector<int>&arr,int start,int end,int x,int res){
+
+      while(start<=end){
+      int mid = start + (end-start)/2;
+
+      if(arr[mid]==x){
+          res = mid;
+          end = mid-1;
+      }
+      else if(arr[mid]<x) start = mid+1;
+      else end = mid-1;
+
+      }
+      return res;
+
+  }
+
+
+  public:
+  int l(vector<int>&arr,int start,int end,int x,int res){
+
+      while(start<=end){
+      int mid = start + (end-start)/2;
+
+      if(arr[mid]==x){
+          res = mid;
+          start = mid+1;
+      }
+      else if(arr[mid]<x) start = mid+1;
+      else end = mid-1;
+
+      }
+      return res;
+
+  }
+
+
+public:
+    vector<int> searchRange(vector<int>& nums, int target) {
+
+        int start = 0;
+        int end = nums.size()-1;
+        int res = -1;
+
+        vector<int>v;
+        int first = f(nums,start,end,target,res);
+        int last  = l(nums,start,end,target,res);
+
+        v.push_back(first);
+        v.push_back(last);
+
+        return v;
+
+
+    }
+};

cpp/0706-design-hashmap.cpp

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+// Design a HashMap without using any built-in hash table libraries.
+
+// Implement the MyHashMap class:
+
+// MyHashMap() initializes the object with an empty map.
+// void put(int key, int value) inserts a (key, value) pair into the HashMap. If the key already exists in the map, update the corresponding value.
+// int get(int key) returns the value to which the specified key is mapped, or -1 if this map contains no mapping for the key.
+// void remove(key) removes the key and its corresponding value if the map contains the mapping for the key.
+
+
+class MyHashMap {
+public:
+
+    unordered_map<int,int> mp;
+
+    MyHashMap() {
+
+    }
+
+    void put(int key, int value) {
+        mp[key] = value;
+    }
+
+    int get(int key) {
+        if(mp.find(key)!=mp.end()) return mp[key];
+        return -1;
+    }
+
+    void remove(int key) {
+        mp.erase(key);
+    }
+};