hdu 5536 Chip Factory（水 | 字典树）

题目链接：hdu 5536 Chip Factory

解题思路

这题时限太松，纯暴力都可以，正解应该是字典树。

代码

#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;
const int maxn = 1e3 + 5;

int N, S[maxn];

int main () {
    int cas;
    scanf("%d", &cas);
    while (cas--) {
        scanf("%d", &N);
        for (int i = 0; i < N; i++) scanf("%d", &S[i]);
        int ans = 0;
        for (int i = 0; i < N; i++) {
            for (int j = i + 1; j < N; j++)
                for (int k = j + 1; k < N; k++) {
                    ans = max(ans, S[i] ^ (S[j] + S[k]));
                    ans = max(ans, S[j] ^ (S[i] + S[k]));
                    ans = max(ans, S[k] ^ (S[i] + S[j]));
                }
        }
        printf("%d\n", ans);
    }
    return 0;
}