Compilare: main.cpp: In function 'int main()': main.cpp:39:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("grade.in", "r", stdin); ^ main.cpp:41:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("grade.out", "w", stdout); ^ main.cpp: In function 'void dfs(int)': main.cpp:13:9: warning: '#'target_mem_ref' not supported by dump_expr#<expression error>' may be used uninitialized in this function [-Wmaybe-uninitialized] int ok[100]; ^~ main.cpp:19:19: warning: '#'target_mem_ref' not supported by dump_expr#<expression error>' may be used uninitialized in this function [-Wmaybe-uninitialized] if(ok[i]==ok[j]) ~~~~^