Compilare: user.cpp: In function ‘void update(int, int, int)’: user.cpp:14:10: warning: statement has no effect [-Wunused-value] for(x;x<=n;x=x+((x^(x-1))&x)) ^ user.cpp: In function ‘int query(int, int)’: user.cpp:20:10: warning: statement has no effect [-Wunused-value] for(x;x>0;x=x-((x^(x-1))&x)) ^ user.cpp: In function ‘void dfs(int)’: user.cpp:29:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<queries[node].size();i++) ^ user.cpp:31:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<g[node].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:37:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("undo.in","r",stdin); ^ user.cpp:38:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("undo.out","w",stdout); ^ user.cpp:40:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:45:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&type); ^ user.cpp:47:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&z); ^ user.cpp:55:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^ user.cpp:61:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^