Compilare: user.cpp: In function ‘int mx(int, int)’: user.cpp:9:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(ind>line[lin].size()) ~~~^~~~~~~~~~~~~~~~~ user.cpp: In function ‘void modify(int, int)’: user.cpp:29:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(pos*2+1<line[k-1].size()) ~~~~~~~^~~~~~~~~~~~~~~~~ user.cpp: In function ‘void solve()’: user.cpp:42:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&q,&a,&b); ^ user.cpp: In function ‘int main()’: user.cpp:55:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arbint.in","r",stdin); ^ user.cpp:56:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arbint.out","w",stdout); ^ user.cpp:57:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:60:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^