arbore.cpp: In function 'void build(int)': arbore.cpp:13: warning: comparison between signed and unsigned integer expressions arbore.cpp:20: warning: comparison between signed and unsigned integer expressions arbore.cpp:30: warning: comparison between signed and unsigned integer expressions arbore.cpp:37: warning: comparison between signed and unsigned integer expressions arbore.cpp: In function 'int main()': arbore.cpp:74: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result arbore.cpp:75: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result