Compilare: user.cpp: In function ‘int main()’: user.cpp:9:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sdo.in", "r", stdin); ^ user.cpp:10:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sdo.out", "w", stdout); ^ user.cpp:11:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &k); ^ user.cpp:13:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", v+i); ^ user.cpp: In function ‘int kthelem(int, int)’: user.cpp:39:1: warning: control reaches end of non-void function [-Wreturn-type] } ^