copaci3.cpp: In function 'void dfs(int)': copaci3.cpp:23: warning: unused variable 't' copaci3.cpp: In function 'int main()': copaci3.cpp:41: warning: unused variable 'T' copaci3.cpp:41: warning: unused variable 'j' copaci3.cpp:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result copaci3.cpp:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result copaci3.cpp:43: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result copaci3.cpp:46: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result copaci3.cpp:80: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result copaci3.cpp:41: warning: 'start' may be used uninitialized in this function