有 N 个正整数 ，已知其中恰好有 K<5000 个数出现的次数均为奇数。请你找出这 K 个数。时间限制 1000ms，空间限制 5MB 要求使用C++17进行解答，1<=N<=3*10^6 所有数字均为int范围内的正整数

#include <cstdio>
#include <cstdint>
#include <algorithm>

namespace io {
    const int BUF_SIZE = 1 << 16;
    char buf[BUF_SIZE];
    int pos = 0, len = 0;
    inline char next_char() {
        if (pos == len) {
            pos = 0;
            len = fread(buf, 1, BUF_SIZE, stdin);
            if (len == 0) return EOF;
        }
        return buf[pos++];
    }
    inline uint32_t read_uint32() {
        uint32_t x = 0;
        char c = next_char();
        while (c < '0' || c > '9') { if (c == EOF) return 0; c = next_char(); }
        while (c >= '0' && c <= '9') { x = x * 10 + (c - '0'); c = next_char(); }
        return x;
    }
    char out_buf[BUF_SIZE];
    int out_pos = 0;
    inline void flush_output() { fwrite(out_buf, 1, out_pos, stdout); out_pos = 0; }
    inline void write_uint32(uint32_t x) {
        if (out_pos >= BUF_SIZE - 20) flush_output();
        if (x == 0) { out_buf[out_pos++] = '0'; out_buf[out_pos++] = '\n'; return; }
        char temp[10]; int tl = 0;
        while (x > 0) { temp[tl++] = '0' + (x % 10); x /= 10; }
        for (int i = tl - 1; i >= 0; i--) out_buf[out_pos++] = temp[i];
        out_buf[out_pos++] = '\n';
    }
}

const int M = 65536;       // 桶数 2^16
const int D = 5;            // 哈希表数量
const int MASK = M - 1;

uint32_t buckets[D][M];     // 1.25 MB
const uint32_t seeds[D] = { 0x12345678, 0x9abcdef0, 0xdeadbeef, 0xfeedface, 0x8badf00d };

inline uint32_t hash(uint32_t x, uint32_t seed) {
    x ^= seed;
    x ^= x >> 16;
    x *= 0x85ebca6b;
    x ^= x >> 13;
    x *= 0xc2b2ae35;
    x ^= x >> 16;
    return x & MASK;
}

uint32_t candidates[50000]; // 0.19 MB （关键优化：从 393216 缩小到 50000）
int candidate_count = 0;

int main() {
    int n = (int)io::read_uint32();
    int k = (int)io::read_uint32();

    // 第一遍：XOR 哈希
    for (int i = 0; i < n; i++) {
        uint32_t x = io::read_uint32();
        for (int d = 0; d < D; d++)
            buckets[d][hash(x, seeds[d])] ^= x;
    }

    // 第二遍：收集无碰撞的候选值
    for (int d = 0; d < D; d++) {
        for (int b = 0; b < M; b++) {
            uint32_t v = buckets[d][b];
            if (v != 0) {
                // 验证：v 单独占据一个桶（无碰撞）
                if (buckets[d][hash(v, seeds[d])] == v) {
                    candidates[candidate_count++] = v;
                }
            }
        }
    }

    // 排序去重
    std::sort(candidates, candidates + candidate_count);
    candidate_count = (int)(std::unique(candidates, candidates + candidate_count) - candidates);

    // 输出
    for (int i = 0; i < candidate_count; i++)
        io::write_uint32(candidates[i]);
    io::flush_output();

    return 0;
}