Compilare: user.cpp: In function ‘void update(int, int, int)’: user.cpp:24:40: warning: suggest parentheses around arithmetic in operand of ‘^’ [-Wparentheses] for( ; px <= n; px += px ^ (px - 1) & px) ^ user.cpp:25:48: warning: suggest parentheses around arithmetic in operand of ‘^’ [-Wparentheses] for(py = sy; py <= n; py += py ^ (py - 1) & py) ^ user.cpp: In function ‘int query(int, int)’: user.cpp:32:36: warning: suggest parentheses around arithmetic in operand of ‘^’ [-Wparentheses] for( ; px; px -= px ^ (px - 1) & px) ^ user.cpp:33:46: warning: suggest parentheses around arithmetic in operand of ‘^’ [-Wparentheses] for(py = sy; py; py -= py ^ (py - 1) & py) ^ user.cpp: In function ‘int main()’: user.cpp:68:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("9-undo.in","r",stdin); ^ user.cpp:69:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("9-undo.out","w",stdout); ^ user.cpp:73:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:77:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&tip); ^ user.cpp:82:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&a,&b,&c); ^ user.cpp:91:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^ user.cpp:98:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&steps); ^