hdu 4825 Xor Sum 位操作 字典樹
阿新 • • 發佈:2019-02-07
遇到本題,在物件成員中申請陣列空間的話,會不明就裡地TLE,而且浪費大量記憶體。
/**
* 2015年7月15日 上午11:21:15
* PrjName:hdu4825
* @ Semprathlon
*/
import java.io.*;
class Trie {
private final int maxd = 33;
private long data;
private Trie ch0, ch1;
void insert(long n) {
Trie rt = this;
for (int i = maxd - 1 ; i >= 0; i--) {
if ((n & (1L << i)) == 0L) {// 0
if (rt.ch0 == null)
rt.ch0 = new Trie();
rt = rt.ch0;
} else {// 1
if (rt.ch1 == null)
rt.ch1 = new Trie();
rt = rt.ch1;
}
if (i == 0)
rt.data = n;
}
}
long query(long n) {
Trie rt = this;
for (int i = maxd - 1; i >= 0; i--) {
if ((n & (1L << i)) > 0L && rt.ch0 != null || rt.ch1 == null)// 0
rt = rt.ch0;
else if (rt.ch1 != null )// 1
rt = rt.ch1;
}
return rt.data;
}
}
public class Main {
public static void main(String[] args) throws IOException {
StreamTokenizer in = new StreamTokenizer(new BufferedReader(
new InputStreamReader(System.in)));
PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
int cas = 0;
in.nextToken();
int T = (int) in.nval;
while (T-- > 0) {
Trie tr = new Trie();
in.nextToken();
int n = (int) in.nval;
in.nextToken();
int m = (int) in.nval;
for (int i = 1; i <= n; i++) {
in.nextToken();
tr.insert((long) in.nval);
}
out.println("Case #" + (++cas) + ":");
for (int i = 1; i <= m; i++) {
in.nextToken();
out.println(tr.query((long) in.nval));
}
}
out.flush();
out.close();
}
}