Compilare: user.cpp: In function ‘int main()’: user.cpp:55:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < L[aux].size(); j ++) { ^ user.cpp:32:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ciclueuler.in", "r", stdin); ^ user.cpp:33:30: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] int n, m, x, y; gets(str); pt(); ^ user.cpp:36:18: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(str); pt(); ^ /tmp/ccQRW85J.o: In function `main': user.cpp:(.text.startup+0x3b): warning: the `gets' function is dangerous and should not be used.