/in/foo.cc: In function 'int main()':
/in/foo.cc:15:5: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
   if((a[i]<=a[i-1]&&a[i]<=a[i+1])||(a[i]>=a[i-1]&&a[i]>=a[i+1]))
     ^