Compilare: user.cpp: In function ‘int main()’: user.cpp:36:29: warning: NULL used in arithmetic [-Wpointer-arith] for(j = 0; ln[j] != NULL; ++ j) ^ user.cpp:28:24: warning: unused variable ‘flag’ [-Wunused-variable] int n, m, i, j, x, flag, cnt; ^ user.cpp:26:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("senat.in", "r", stdin); ^ user.cpp:27:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("senat.out", "w", stdout); ^ user.cpp:31:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d\n", &n, &m); ^ user.cpp:33:17: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(ln); ^ /tmp/cciN4Rir.o: In function `main': user.cpp:(.text.startup+0x9c): warning: the `gets' function is dangerous and should not be used.