先搞清楚这个数不一定是二叉树,然后把树分段,把所有子树用队列存放。搞清楚BFS和DFS的关系就很明确了。
AC代码:
#include <iostream> #include <cstdio> #include <cstdlib> #include <cctype> #include <cstring> #include <string> #include <sstream> #include <vector> #include <set> #include <map> #include <algorithm> #include <stack> #include <queue> #include <bitset> #include <cassert> #include <cmath> using namespace std; const int maxn = 1005; struct Seg { int lef, rig; Seg(int lef, int rig) : lef(lef), rig(rig) {} }; queue<Seg> q; vector<int> v[maxn]; int bfs[maxn], dfs[maxn]; int n; void solve() { // 整个数先入队 q.push(Seg(0, n)); int p = 1; int root; while (!q.empty()) { Seg s = q.front(); q.pop(); if (s.rig - s.lef <= 1 || p == n) { continue; } root = dfs[s.lef]; int pre = s.lef + 1; // 分离根结点 // 在dfs中往下找子树 for (int i = pre; i < s.rig; i++) { if (dfs[i] == bfs[p]) { q.push(Seg(pre, i)); v[root].push_back(dfs[i]); p++; pre = i; } } if (pre < s.rig) { q.push(Seg(pre, s.rig)); } } } int main() { ios::sync_with_stdio(false); while (cin >> n) { for (int i = 0; i < n; i++) { cin >> bfs[i]; } for (int i = 0; i < n; i++) { cin >> dfs[i]; } solve(); for (int i = 1; i <= n; i++) { cout << i << ":"; for (int j = 0; j < v[i].size(); j++) { cout << " " << v[i][j]; } cout << endl; v[i].clear(); } } return 0; }