Compilare: main.cpp: In function 'int main()': main.cpp:126:13: warning: variable 'st' set but not used [-Wunused-but-set-variable] int st,dr,sol; ^~ main.cpp:126:16: warning: variable 'dr' set but not used [-Wunused-but-set-variable] int st,dr,sol; ^~ main.cpp:68:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("diff.in","r",stdin); ^ main.cpp:69:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("diff.out","w",stdout); ^ main.cpp:71:28: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buff,1,dim,stdin); ^ main.cpp: In function 'void read(int&)': main.cpp:49:36: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buff,1,dim,stdin); ^ main.cpp:60:36: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buff,1,dim,stdin); ^