tgv.cpp: In function 'void DFS(int, int)': tgv.cpp:20: warning: comparison between signed and unsigned integer expressions tgv.cpp:24: warning: comparison between signed and unsigned integer expressions tgv.cpp:27: warning: comparison between signed and unsigned integer expressions tgv.cpp:35: warning: comparison between signed and unsigned integer expressions tgv.cpp:18: warning: unused variable 'J' tgv.cpp: In function 'int main()': tgv.cpp:47: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result tgv.cpp:48: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result tgv.cpp:49: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result tgv.cpp:51: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result tgv.cpp: In function 'void DFS(int, int)': tgv.cpp:18: warning: 'I' may be used uninitialized in this function