arrow.cpp: In function 'int main()':
arrow.cpp:16:18: error: 'n' was not declared in this scope
sort(arr,arr+n);
^
arrow.cpp:13:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d",&N);
~~~~~^~~~~~~~~
arrow.cpp:15:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%lld%lld",&arr[i].w,&arr[i].ipt);
~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~