Compilare: user.cpp: In function ‘int main()’: user.cpp:22:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d%d",&N,&M,&K); ^ user.cpp:29:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&c[i]); ^ user.cpp:33:40: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d%d",&x,&y,&z); ^ user.cpp:68:18: warning: ‘k’ may be used uninitialized in this function [-Wmaybe-uninitialized] viz[k]=1; ^