Erase function Unordered map

#1

the code is giving segmentation fault in codingblocks ide
but works fine in other ide’s like ideone - https://ideone.com/oPgJSM , codechef

Also , the map size is not decreasing on removing elements can you explain why ??

#2

Because when you erase from the an unordered map, your iterator can be invalid in some cases