Compilare: main.cpp: In function 'void add_edge(int)': main.cpp:90:9: warning: unused variable 'z' [-Wunused-variable] int z=edges[i].z; ^ main.cpp: In function 'int main()': main.cpp:97:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pscnv.in","r",stdin); ^ main.cpp:98:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pscnv.out","w",stdout); ^ main.cpp:100:28: 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:33:36: 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:44:36: 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); ^