From 3e87c2f08b000cdebe919d1d581002cabb016f7c Mon Sep 17 00:00:00 2001
From: Jidong Xiao <xiaoj8@rpi.edu>
Date: Sat, 11 Nov 2023 23:36:30 -0500
Subject: [PATCH] adding another unordered map problem

---
 leetcode/p2150_lonely_numbers.cpp | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 leetcode/p2150_lonely_numbers.cpp

diff --git a/leetcode/p2150_lonely_numbers.cpp b/leetcode/p2150_lonely_numbers.cpp
new file mode 100644
index 0000000..3890fa2
--- /dev/null
+++ b/leetcode/p2150_lonely_numbers.cpp
@@ -0,0 +1,23 @@
+class Solution {
+public:
+    vector<int> findLonely(vector<int>& nums) {
+        int size = nums.size();
+        std::vector<int> result;
+        std::unordered_map<int, int> map1;
+        // count how many times each number appears
+        for(int i=0;i<size;i++){
+            map1[nums[i]]++;
+        }
+        std::unordered_map<int, int>::iterator itr = map1.begin();
+        while(itr != map1.end()){
+            if(itr->second==1){
+                // if neither adjacent number exists
+                if(map1.find(itr->first-1)==map1.end() && map1.find(itr->first+1)==map1.end()){
+                    result.push_back(itr->first);
+                }
+            }
+            itr++;
+        }
+        return result;
+    }
+};