Compilare: user.cpp: In function ‘int main()’: user.cpp:45:15: warning: unused variable ‘a’ [-Wunused-variable] int i=0,j,a=1,b=1,nrc; ^ user.cpp:45:19: warning: unused variable ‘b’ [-Wunused-variable] int i=0,j,a=1,b=1,nrc; ^ user.cpp:45:23: warning: unused variable ‘nrc’ [-Wunused-variable] int i=0,j,a=1,b=1,nrc; ^ user.cpp:46:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("perm2.in","r",stdin); ^ user.cpp:47:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("perm2.out","w",stdout); ^ user.cpp:48:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:50:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^