true和false的01背包，最大容量为总量/2

true和false的01背包，最大容量为总量/2
  总数为奇数直接输出false结束
import java.io.*;
import java.util.*;

public class Main {
	public static void main(String[] args) throws IOException {
		int n = nextInt();
		int[] list = new int[n];
		int sum = 0;
		for (int i = 0; i < list.length; i++) {
			list[i] = nextInt();
			sum += list[i];
		}
		if(sum%2==1) {
			System.out.println(false);
			return;
		}
		boolean[] dp = new boolean[sum / 2+1];
		dp[0] = true;
		for (int i = 0; i < n; i++) {
			for (int j = sum/2; j >= list[i]; j--) {
				if(dp[j-list[i]])
					dp[j] = true;
			}
		}
		System.out.println(dp[sum/2]);
	}
	
	
	
	
	
	
	
	
	
	
	static PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));
	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	static StreamTokenizer st = new StreamTokenizer(br);
	static int nextInt() throws IOException {
		st.nextToken();
		return (int) st.nval;
	}
	static long nextLong() throws IOException {
		st.nextToken();
		return (long) st.nval;
	}
}