ACM Q11296

import java.util.Scanner;
public class Q11296 {
  public static void main(String args[]) {
    Scanner cin = new Scanner(System.in);
    long  n;
    while(cin.hasNextInt() ){
      n = cin.nextInt();
      if(n > 1000001){
        continue;
      }
      long count=0;
        count = (n/2+1)*(n/2+2)/2;
      System.out.println(count);
    }

  }
}

利用公式解!!!

import java.util.Scanner;
public class Q11296 {
  public static void main(String args[]) {
    Scanner cin = new Scanner(System.in);
    int  n;
    while(cin.hasNextInt() ){
      n = cin.nextInt();
      if(n > 1000001){
        continue;
      }
      long count=0;
      for(int x=n%2; x<=n ;x=x+2){
        count += (n-x)/2+1;
      }
      System.out.println(count);
    }

  }
}

不用公式解!!!