Compilare: user.cpp: In function ‘void read()’: user.cpp:24: warning: unused variable ‘j’ user.cpp:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘int df(int, int)’: user.cpp:45: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int df2(int, int)’: user.cpp:57: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void df3(int, int)’: user.cpp:78: warning: comparison between signed and unsigned integer expressions user.cpp:66: warning: unused variable ‘s’ user.cpp: In function ‘void solve()’: user.cpp:147: warning: comparison between signed and unsigned integer expressions user.cpp:160: warning: comparison between signed and unsigned integer expressions user.cpp:125: warning: ‘x’ may be used uninitialized in this function