Compilare: user.cpp: In function ‘void read()’: user.cpp:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:46: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void pairing(int)’: user.cpp:63: warning: comparison between signed and unsigned integer expressions user.cpp:73: warning: comparison between signed and unsigned integer expressions user.cpp:86: warning: comparison between signed and unsigned integer expressions user.cpp:89: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void dfs(int, int)’: user.cpp:135: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void write()’: user.cpp:177: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:187: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result