salvare.cpp: In function 'void DFS(int, int)': salvare.cpp:15: warning: comparison between signed and unsigned integer expressions salvare.cpp: In function 'int main()': salvare.cpp:66: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result salvare.cpp:67: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result salvare.cpp:68: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result salvare.cpp:78: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result