48 lines
1.1 KiB
C++
48 lines
1.1 KiB
C++
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#include <bits/stdc++.h>
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using namespace std;
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int preorder[1010];
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int inorder[1010];
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int n;
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struct TreeNode {
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int val;
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TreeNode *lc;
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TreeNode *rc;
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TreeNode(int v) : val(v) {}
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TreeNode(int v, TreeNode *l, TreeNode *r) : val(v), lc(l), rc(r) {}
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};
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TreeNode* dfs(int p_begin, int p_end, int i_begin, int i_end) {
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if (i_begin >= i_end) {
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return nullptr;
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}
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auto i_mid = find(inorder + i_begin, inorder + i_end, preorder[p_begin]) - inorder;
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int left_sz = i_mid - i_begin;
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TreeNode* res = new TreeNode(preorder[p_begin]);
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res->lc = dfs(p_begin + 1, p_begin + 1 + left_sz, i_begin, i_mid);
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res->rc = dfs(p_begin + 1 + left_sz, p_end, i_mid + 1, i_end);
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return res;
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}
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void print_postorder(TreeNode *node) {
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if (!node) {
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return;
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}
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print_postorder(node->lc);
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print_postorder(node->rc);
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cout << node->val << ' ';
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}
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int main() {
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cin >> n;
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for (int i = 0; i < n; ++i) {
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cin >> preorder[i];
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}
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for (int i = 0; i < n; ++i) {
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cin >> inorder[i];
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}
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print_postorder(dfs(0, n, 0, n));
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return 0;
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}
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