Compilare: user.cpp: In function 'void df1(int)': user.cpp:55: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'void df2(int)': user.cpp:69: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'void df3(int)': user.cpp:81: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'void df4(int)': user.cpp:99: warning: comparison between signed and unsigned integer expressions user.cpp:94: warning: unused variable 'j' user.cpp: In function 'void solve()': user.cpp:161: warning: comparison between signed and unsigned integer expressions user.cpp:184: warning: comparison between signed and unsigned integer expressions user.cpp:200: warning: comparison between signed and unsigned integer expressions user.cpp:206: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'int solution(int, int)': user.cpp:222: warning: unused variable 'i' user.cpp: In function 'void writedata()': user.cpp:245: warning: operation on 'v1' may be undefined