HDU 5536 Chip Factory

来源：互联网发布：知らない打ち合わせ编辑：程序博客网时间：2024/05/29 18:26

这题我做了三次，三次都把异或看成了与，真心无语

一道基础字典树，记住初始化根

#include <cstdio>#include <algorithm>using namespace std;struct Trie{    Trie *next[2];    int cnt;};Trie *root = new Trie;void init(Trie *p){    p->next[0] = p->next[1] = NULL;    p->cnt = 1;}void insert(char *p, int add){    Trie *now = root, *newnode;    while(*p != '\0' && now ->next[*p - '0'] != NULL)    {        now = now->next[*p++ - '0'];        now->cnt += add;    }    while(*p != '\0')    {        newnode = new Trie;        init(newnode);        now->next[*p++ - '0'] = newnode;        now = newnode;    }}int query(char *p){    Trie *now = root;    int res = 0;    while(*p != '\0')    {        res <<= 1;        int t = (*p++ - '0') ^ 1;        if(now->next[t] != NULL && now->next[t]->cnt != 0)            now = now->next[t], res++;        else            now = now->next[t^1];    }    return res;}int a[1005];char s[35];void toString(int t){    for(int i = 31; i >= 0; i--)        s[i] = '0' + (t & 1), t >>= 1;    s[32] = '\0';}int main(){    int T;    scanf("%d", &T);    while(T--)    {        init(root);        int n;        scanf("%d", &n);        for(int i = 0; i < n; i++)        {            scanf("%d", &a[i]);            toString(a[i]);            insert(s, 1);        }        int Max = 0;        for(int i = 0; i < n; i++)        {            toString(a[i]);            insert(s, -1);            for(int j = i + 1; j < n; j++)            {                toString(a[j]);                insert(s, -1);                toString(a[i] + a[j]);                Max = max(Max, query(s));                toString(a[j]);                insert(s, 1);            }            toString(a[i]);            insert(s, 1);        }        printf("%d\n", Max);    }    return 0;}

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