Xor Sum HDU - 4825(01字典树)

Posted 2020-10-12 yijiull

 

Xor Sum

HDU - 4825

(orz从之前从来没见过这种题

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 #define LL long long
 4 const int maxnode = 100010 * 32;
 5 const int sigma = 2;
 6 struct AC01{
 7     int ch[maxnode][sigma];
 8     LL val[maxnode];
 9     int sz;
10     void init(){
11         sz = 1;
12         val[0] = 0;
13         memset(ch[0], 0, sizeof(ch[0]));
14     }
15     void add(LL x){
16         int u = 0, n = 32;
17         for(int i = n; i >= 0; i--){
18             int c = (x >> i) & 1;
19             if(!ch[u][c]){
20                 memset(ch[sz], 0, sizeof(ch[sz]));
21                 val[sz] = 0;
22                 ch[u][c] = sz++;
23             }
24             u = ch[u][c];
25         }
26         val[u] = x;
27     }
28     //返回与x异或最大的值val[u];
29     LL query(LL x){
30         int u = 0, n = 32;
31         for(int i = n; i >= 0; i--){
32             int c = (x >> i) & 1;
33             if(ch[u][c ^ 1]) u = ch[u][c ^ 1];
34             else u = ch[u][c];
35         }
36         return val[u];
37     }
38 }ac;
39 int main(){
40     int t, kase = 0;
41     //freopen("in.txt", "r", stdin);
42     scanf("%d", &t);
43     while(t--){
44         ac.init();
45         int n, q;
46         scanf("%d %d", &n, &q);
47         for(int i = 0; i < n; i++) {
48             LL x;
49             scanf("%lld", &x);
50             ac.add(x);
51         }
52         printf("Case #%d:\n", ++kase);
53         while(q--){
54             LL x;
55             scanf("%lld", &x);
56             LL temp = ac.query(x);
57             printf("%lld\n", temp);
58         }
59     }
60 }

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