1356

E_1356_SortIntegersbyTheNumberof1Bits.cpp

@@ -0,0 +1,25 @@
+class Solution {
+public:
+    vector<int> sortByBits(vector<int>& arr) {
+        multiset<pair<int,int>> ms;
+        for (int i =0; i<arr.size(); i++){
+            int num1s = numof1(arr[i]);
+            ms.insert({num1s,arr[i]}); 
+        }
+        vector<int> res;
+        for(auto el: ms){
+            res.push_back(el.second);
+        }
+        return res;
+
+    }
+
+    int numof1(int num){
+        int cnt=0;
+        while(num){
+            cnt+=num&1;
+            num>>=1;
+        }
+        return cnt;
+    }
+};