Compilare: user.cpp: In function ‘void P1()’: user.cpp:18:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 3; i <= k; ++i) ^ user.cpp: In function ‘void P2()’: user.cpp:27:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i <= n; ++i) ^ user.cpp:32:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = n + 1; i <= k; ++i) ^ user.cpp: In function ‘int main()’: user.cpp:41:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i <= n; ++i) f >> v[i], minim = min(minim, v[i]); ^