Compilare: user.cpp: In function ‘int main()’: user.cpp:55:39: warning: unused variable ‘start’ [-Wunused-variable] int N = get_int(), M = get_int(), start = get_int(); ^~~~~ user.cpp: At global scope: user.cpp:43:37: warning: always_inline function might not be inlinable [-Wattributes] __attribute__((always_inline)) void pass_int() ^~~~~~~~ user.cpp:31:36: warning: always_inline function might not be inlinable [-Wattributes] __attribute__((always_inline)) int get_int() ^~~~~~~ user.cpp: In function ‘int main()’: user.cpp:50:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dfs.in", "r", stdin); ^ user.cpp:51:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dfs.out", "w", stdout); ^ user.cpp:53:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, 1, 20000000, stdin); ^