gondola.cpp: In function 'int valid(int, int*)':
gondola.cpp:16:9: error: no match for 'operator[]' (operand types are 'std::set<int>' and 'int')
16 | if(a[x].count!=0){
| ^
gondola.cpp: In function 'int replacement(int, int*, int*)':
gondola.cpp:41:1: warning: no return statement in function returning non-void [-Wreturn-type]
41 | }
| ^
gondola.cpp: In function 'int countReplacement(int, int*)':
gondola.cpp:46:1: warning: no return statement in function returning non-void [-Wreturn-type]
46 | }
| ^