Compilare: user.cpp: In function ‘void solve()’: user.cpp:53:45: warning: operation on ‘nr’ may be undefined [-Wsequence-point] pos[++ nr] = pos[nr - 1] + 1; ^ user.cpp: In function ‘void read()’: user.cpp:20:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("seti.in", "r", stdin); ^ user.cpp:21:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &n); ^ user.cpp:24:30: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(S, maxM, stdin); ^ user.cpp: In function ‘void write()’: user.cpp:102:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("seti.out", "w", stdout); ^ user.cpp:103:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &m); ^ user.cpp:106:30: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(S, maxl, stdin); ^