Compilare: user.cpp: In function ‘int main()’: user.cpp:63:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<sol.size();i++) fprintf(g,"%d ",sol[i]); ^ user.cpp: In function ‘void pre()’: user.cpp:26:21: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%s",A); ^ user.cpp: In function ‘void solve()’: user.cpp:40:21: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%s",B); ^