Compilare: main.cpp: In function 'void update(int, int, int)': main.cpp:22:41: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses] for( ; px <= n; px += px ^ (px - 1) & px) ~~~~~~~~~^~~~ main.cpp:23:48: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses] for(py = sy; py <= n; py += py ^ (py - 1) & py) ~~~~~~~~~^~~~ main.cpp: In function 'int query(int, int)': main.cpp:29:36: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses] for( ; px; px -= px ^ (px - 1) & px) ~~~~~~~~~^~~~ main.cpp:30:46: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses] for(py = sy; py; py -= py ^ (py - 1) & py) ~~~~~~~~~^~~~ main.cpp: In function 'int main()': main.cpp:59:30: 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); ^ main.cpp:60:32: 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); ^ main.cpp:62:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ main.cpp:66:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&tip); ^ main.cpp:71:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&a,&b,&c); ^ main.cpp:80:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^ main.cpp:87:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&steps); ^