Compilare: user.cpp: In function ‘int main()’: user.cpp:16:24: warning: unused variable ‘ec1’ [-Wunused-variable] long long j, n, k, ec1=0, ec2=0, i, a, b, c, d, fe2=0, f2=0, fe1=0, f1=0, x; ^ user.cpp:16:31: warning: unused variable ‘ec2’ [-Wunused-variable] long long j, n, k, ec1=0, ec2=0, i, a, b, c, d, fe2=0, f2=0, fe1=0, f1=0, x; ^ user.cpp:18:10: warning: variable ‘cc’ set but not used [-Wunused-but-set-variable] char cc; ^ user.cpp:14:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ec.in", "r", stdin); ^ user.cpp:15:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ec.out", "w", stdout); ^ user.cpp:19:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld\n", &n, &k); ^ user.cpp:22:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &x); ^ user.cpp:31:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ /tmp/ccaYsYW3.o: In function `main': user.cpp:(.text.startup+0x179): warning: the `gets' function is dangerous and should not be used.