Problem	missingnumber
User	tonk
Submission Time	2025-12-24 22:51:25
Score	0
Max Time	N/A
Max Memory	N/A

Compile Error

missingnumber.cpp: In function ‘int main()’:
missingnumber.cpp:15:9: error: ‘seen’ was not declared in this scope
15 | seen[x] = 1;
| ^~~~