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原创最新推荐文章于 2026-03-13 19:45:02 发布 258 阅读 AI 写同款· GEO 优化 ›

深度学习笔记（3）——kernel（内核）与filter（滤波器）本文仅仅简单介绍了kernel和filter的概念，介绍了确定filter和kernel个数的方法。阅读详情

#include <iostream>
#include <cstdio>
#include<algorithm>
using namespace std;

const int N = 1005;
int a[N];
int n,m;

struct Node{
    int val;
    Node* next[2];
    Node(){
        val = 0;
        next[0] = next[1] = NULL;
    }

    void add(int number){
        Node* tmp = this;
        for (int i = 31; i >=0; i--){
            int op = (number & (1 << i)) > 0 ? 1:0;
            if (tmp->next[op] == NULL){
                tmp->next[op] = new Node();
            }
            tmp = tmp->next[op];
            tmp->val++;
        }
    }

    void del(int number){
        Node* tmp = this;
            for (int i = 31; i >=0; i--){
                int op = (number & (1 << i)) > 0 ? 1:0;
                tmp = tmp->next[op];
                tmp->val--;
            }
    }

    int query(int value){
        int ans = 0;
        Node* tmp = this;
        for (int i = 31; i>=0; i--){
            int op = (value & (1 << i)) > 0 ? 1 : 0;
            op = op ^ 1;
            //为什么这里面不用担心NULL,首先肯定是有一个数在tree中
            //那么tree 中肯定存在一条从头到尾的路径.
            if (tmp->next[op] && tmp->next[op]->val){
                ans += (1 << i);
                tmp = tmp->next[op];
            }else{
                tmp = tmp->next[op^1];
            }
        }
        return ans;
    }
};


void del(Node* node){
    if (node == NULL)
        return;
    if (node->next[0]){
        del(node->next[0]);
    }
    if (node->next[1]){
        del(node->next[1]);
    }
    delete(node);
}

int main()
{
    int t = 0;
    scanf("%d", &t);
    Node *node = NULL;
    while (t--){
        scanf("%d", &n);

        for (int i = 0; i < n; i++){
            scanf("%d", &a[i]);
        }
        del(node);
        node = new Node();
        for (int i = 0; i < n; i++){
            node->add(a[i]);
        }

        int ans = 0;
        for (int i = 0; i < n; i++){
            for (int j = i + 1; j < n; j++){
                node->del(a[i]);
                node->del(a[j]);
                ans = max(ans, node->query(a[i] + a[j]));
                node->add(a[i]);
                node->add(a[j]);
            }
        }
        printf("%d\n", ans);
    }
    return 0;
}
/*

2
3
1 2 3
3
100 200 300


6
400
*/

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