Compilare: main.cpp: In function 'void read()': main.cpp:13:11: warning: unused variable 'y' [-Wunused-variable] { int x,y,k=0; ^ main.cpp:14:28: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&n,&m); ^ main.cpp:17:26: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&x); ^ main.cpp: In function 'void solve()': main.cpp:37:34: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&x,&niv); ^