L2-011 玩轉二叉樹 (25分)

L2-011 玩轉二叉樹 (25分)

AC代碼

#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
struct node{
    int id, index, level;
};
vector<node> pre, in, op;
void Invert(int root, int start, int end, int index, int level){
    if(start > end) return;
    int i = start;
    while (i < end && in[i].id != pre[root].id) i++;
    op.push_back({pre[root].id, index, level});
    Invert(root+i-start+1, i+1, end, index*2+1, level+1);
    Invert(root+1, start, i-1, index*2+2, level+1);
}
bool cmp(node x, node y){
    if (x.level != y.level) return x.level < y.level;
    return x.index < y.index;
}
int main(){
    int n, num;
    scanf("%d", &n);
    for (int i = 0; i < n; i++){
        scanf("%d", &num);
        in.push_back({num, 0, 0});
    }
    for (int i = 0; i < n; i++){
        scanf("%d", &num);
        pre.push_back({num, 0, 0});
    }
    Invert(0, 0, n-1, 0, 0);
    sort(op.begin(), op.end(), cmp);
    printf("%d", op[0].id);
    for (int i = 1; i < n; i++)
        printf(" %d", op[i].id);
    return 0;
}