Compilare: user.cpp: In function ‘int main()’: user.cpp:12:15: warning: unused variable ‘ok’ [-Wunused-variable] int n,i,j,ok,m,op,sum,io,c; ^ user.cpp:57:9: warning: unused variable ‘br’ [-Wunused-variable] int br,lin,col; ^ user.cpp:13:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&n); ^ user.cpp:22:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&z[i]); ^ user.cpp:60:5: warning: ‘op’ may be used uninitialized in this function [-Wmaybe-uninitialized] for(i=2; i<=io; ++i) ^