add codeforces solutions folder

leetcode/lc401/enumerateHrsMins.cpp

@@ -0,0 +1,14 @@
+class Solution{
+    public : 
+        vector<string> readBinaryWatch(int turnedOn){
+            vector<string> ans;
+            for(int h=0;h<12;++h){
+                for(int m = 0;m<60;++m){
+                    if(__builtin_popcount(h)+ __builtin_popcount(m) == turnedOn){
+                        ans.push_back(to_string(h)+":"+(m<10?"0":"")+to_string(m));
+                    }
+                }
+            }
+            return ans;
+        }
+}