Eroare de compilare: user.cpp: In function ‘void citire()’: user.cpp:11: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:12: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:13: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void calcul()’: user.cpp:23: error: ‘exit’ was not declared in this scope user.cpp:24: error: ‘exit’ was not declared in this scope user.cpp:25: error: ‘exit’ was not declared in this scope user.cpp:19: warning: unused variable ‘p’ user.cpp: In function ‘void dfs(int)’: user.cpp:36: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:46: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result