两两比较,注意不要越界就行
import java.util.Arrays;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int a[] = new int[n];
for(int i=0;i<n;i++) {
a[i] = sc.nextInt();
}
Arrays.sort(a);
int count = 0;
for(int j=1;j<n;j++) {
if(a[j]-a[j-1] == 1) {
count++;
}
}
sc.close();
System.out.println(count);
}
}