Compilare: user.cpp: In function ‘int main()’: user.cpp:16:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1;i <= N;i ++) ^ user.cpp:26:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1;i <= L;i ++) f >> v[i]; ^ user.cpp:28:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1;i <= N;i ++) ^ user.cpp:31:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 1;j <= L;j ++) ^