arrow.cpp: In function 'int main()':
arrow.cpp:25:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (j=0; j<ar[i].size(); j++) {
~^~~~~~~~~~~~~
arrow.cpp:27:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
b=(j<ar[i].size()-1?ar[i][j+1]:-(1<<30));
~^~~~~~~~~~~~~~~
arrow.cpp:15:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &N);
~~~~~^~~~~~~~~~
arrow.cpp:19:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &a, &b);
~~~~~^~~~~~~~~~~~~~~~~