Compilare: user.cpp: In function ‘int main()’: user.cpp:258:15: warning: unused variable ‘j’ [-Wunused-variable] int m, i, j, st, dr, k, lim; ^ user.cpp:256:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ( "rev.in", "r", stdin ); ^ user.cpp:257:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ( "rev.out", "w", stdout ); ^ user.cpp:259:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d%d", &n, &m ); ^ user.cpp:269:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d%d%d", &st, &dr, &k ); ^