Compilare: user.cpp: In function ‘int main()’: user.cpp:16:10: warning: variable ‘n’ set but not used [-Wunused-but-set-variable] int t, n, i, k, r, nrresturi, inv2, inv10; ^ user.cpp:16:13: warning: unused variable ‘i’ [-Wunused-variable] int t, n, i, k, r, nrresturi, inv2, inv10; ^ user.cpp:16:19: warning: unused variable ‘r’ [-Wunused-variable] int t, n, i, k, r, nrresturi, inv2, inv10; ^ user.cpp:16:22: warning: unused variable ‘nrresturi’ [-Wunused-variable] int t, n, i, k, r, nrresturi, inv2, inv10; ^ user.cpp:16:33: warning: variable ‘inv2’ set but not used [-Wunused-but-set-variable] int t, n, i, k, r, nrresturi, inv2, inv10; ^ user.cpp:16:39: warning: variable ‘inv10’ set but not used [-Wunused-but-set-variable] int t, n, i, k, r, nrresturi, inv2, inv10; ^ user.cpp:14:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("twosets.in", "r", stdin); ^ user.cpp:15:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("twosets.out", "w", stdout); ^ user.cpp:17:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &t); ^ user.cpp:22:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(input); ^ /tmp/ccvDvWLY.o: In function `main': user.cpp:(.text.startup+0x7b): warning: the `gets' function is dangerous and should not be used.