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32 lines
671 B
32 lines
671 B
#include <bits/stdc++.h>
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using namespace std;
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const int N = 100010;
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int q[N];
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int n, k;
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void quick_sort(int q[], int l, int r, int k) {
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if (l >= r) return;
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int i = l - 1, j = r + 1, x = q[(l + r) >> 1];
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while (i < j) {
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do i++;
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while (q[i] < x);
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do j--;
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while (q[j] > x);
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if (i < j) swap(q[i], q[j]);
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}
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int len = j - l + 1; // 左侧长度
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if (k <= len)
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quick_sort(q, l, j, k); // 左侧
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else
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quick_sort(q, j + 1, r, k - len); // 右侧
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}
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int main() {
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cin >> n >> k;
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for (int i = 1; i <= n; i++) cin >> q[i];
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quick_sort(q, 1, n, k);
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printf("%d", q[k]);
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return 0;
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}
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