arrow.cpp: In function 'int main()':
arrow.cpp:32:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(j=1; j+1<V[i].size(); j++) ans+=min(V[i][j+1]-V[i][j], V[i][j]-V[i][j-1]);
~~~^~~~~~~~~~~~
arrow.cpp:18:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &N);
~~~~~^~~~~~~~~~
arrow.cpp:22:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &x, &y);
~~~~~^~~~~~~~~~~~~~~~