36 lines
837 B
C++
36 lines
837 B
C++
#include <algorithm>
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#include <cstdio>
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#include <cstring>
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#include <iostream>
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using namespace std;
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typedef long long LL;
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typedef long double LDB;
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const int kMaxN = 1e5 + 10;
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int n, key[kMaxN], w[kMaxN];
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int stk[kMaxN], ls[kMaxN], rs[kMaxN];
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void dfs(int rt) {
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printf("%d ", rt);
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if (ls[rt]) dfs(ls[rt]);
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if (rs[rt]) dfs(rs[rt]);
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}
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int main() {
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#ifdef local
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freopen("pro.in", "r", stdin);
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#endif
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scanf("%d", &n);
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for (int i = 1; i <= n; i++) {
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scanf("%d", &key[i]);
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w[key[i]] = i;
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}
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int top = 0;
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for (int i = 1; i <= n; i++) {
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int k = top;
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while (k > 0 && w[stk[k]] > w[i]) k--;
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if (k) rs[stk[k]] = i; // rs代表笛卡尔树每个节点的右儿子
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if (k < top) ls[i] = stk[k + 1]; // ls代表笛卡尔树每个节点的左儿子
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stk[++k] = i;
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top = k;
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}
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dfs(stk[1]);
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return 0;
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} |