Compilare: user.cpp: In function ‘int main()’: user.cpp:29:26: warning: suggest parentheses around assignment used as truth value [-Wparentheses] if(a[i]=0) ^ user.cpp:14:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d %d",&n,&m); ^ user.cpp:22:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&op); ^