1 1= 1 2 2= 4 3 3= 9 4 4= 16 5 5= 25 6 6= 36 7 7= 49 8 8= 64 9 9= 81 10 10= 100
https://www.jdoodle.com/c-online-compiler
I copied and pasted the code from GitHub (click copy, rather than highlighting and copying).
It ran but also outputted the number sequence a few times.
It is possible when you did copy n paste the special characters were lost.
1 1= 1 2 2= 4 3 3= 9 4 4= 16 5 5= 25 6 6= 36 7 7= 49 8 8= 64 9 9= 81 10 10= 100