Compilare: user.cpp: In function ‘void enter(trie, char*, int, int)’: user.cpp:18:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(pos == strlen(s)) ^ user.cpp: In function ‘void solve(int*, int)’: user.cpp:32:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(l[q[i]].size() <= m || l[q[i]][m] != l[q[0]][m]){ ^ user.cpp: In function ‘int main()’: user.cpp:68:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ratina.in", "r", stdin); ^ user.cpp:69:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ratina.out", "w", stdout); ^ user.cpp:70:28: 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:73:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s\n", s); ^ user.cpp:79:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ user.cpp:82:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &q[j]); ^