import java.util.Arrays;
public class Test{
public static boolean judge(int[]arr) {
if(arr==null||arr.length<=0) {
return false;
}
int root = arr[arr.length-1];
int i=0;
for(;i<arr.length-1;i++) {
if(arr[i]>root) {
break;
}
}
int j=i;
for(;j<arr.length-1;j++) {
if(arr[j]<root) {
return false;
}
}
boolean left=true;
if(i>0) {
left=judge(Arrays.copyOfRange(arr, 0, i));
}
boolean right=true;
if(i<arr.length-1) {
right=judge(Arrays.copyOfRange(arr, 0, arr.length-1));
}
return left&&right;
}
public static void main(String[] args) {
int[]arr={1,3,2,5,7,6,4,9,11,10,8};
System.out.println(judge(arr));
}
}