Compilare: user.cpp: In function ‘int main()’: user.cpp:5:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("divk.in", "r", stdin); ^ user.cpp:6:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("divk.out", "w", stdout); ^ user.cpp:10:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d", &n, &k, &a, &b); ^ user.cpp:15:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^ user.cpp:21:17: warning: ‘sol’ may be used uninitialized in this function [-Wmaybe-uninitialized] sol += r[v[i]]; ^