Mã chấm: 268101

Main.cc: In function ‘int main()’:
Main.cc:12:9: error: redeclaration of ‘int n’
     int n = 0;
         ^
Main.cc:8:9: note: ‘int n’ previously declared here
     int n;
         ^
Main.cc:9:11: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf ("%d",&n);
     ~~~~~~^~~~~~~~~