Compilare: user.cpp: In function ‘bool ok(int, int)’: user.cpp:42:7: warning: unused variable ‘ind’ [-Wunused-variable] int ind = 1; ^~~ user.cpp: In function ‘void solve(int, int, int)’: user.cpp:71:7: warning: variable ‘last’ set but not used [-Wunused-but-set-variable] int last = INF; ^~~~ user.cpp: In function ‘int main()’: user.cpp:86:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cangrena.in", "r", stdin); ^ user.cpp:87:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cangrena.out", "w", stdout); ^ user.cpp:90:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:92:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i]); ^ user.cpp:101:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &u, &v); ^