pat 1043

YES和NO写成了，Yes和No导致了一开始一个点都没有过，哭晕%>_<%

#include<iostream>

using std::cin;
using std::cout;
using std::endl;

struct BST{
    int num;
    struct BST *left, *right;
} *T;
int Flag;
struct BST *BuildTree(int a[], int n, int flag){
    int i;
    if (n <= 0)
        return NULL;
    else {
        struct BST *t = new struct BST;
        i = 1;
        t->num = a[0];
        if (flag){
            while (i < n&&a[i] < a[0]){
                i++;
            }
            if (i + 1 < n&&a[i + 1] < a[0])
                Flag = 1;
        }
        else {
            while (i < n&&a[i] >= a[0]){
                i++;
            }
            if (i + 1 < n&&a[i + 1] >= a[0])
                Flag = 1;
        }
        t->left = BuildTree(&a[1], i - 1, flag);
        t->right = BuildTree(&a[i], n - i, flag);
        return t;
    }
}

void PostPrint(struct BST *t){
    if (t){
        PostPrint(t->left);
        PostPrint(t->right);
        if (t == T)
            cout << t->num << endl;
        else cout << t->num << " ";
    }
}
int main(){
    int n, i;
    freopen("1.in", "r", stdin);
    cin >> n;
    int *a = new int[n];
    for (i = 0; i < n; i++)
        cin >> a[i];
    int tag;
    if (n <=2)
        tag = 1;
    else if (a[0] > a[1])
        tag = 1;
    else if (a[0] <= a[1])
        tag = 0;
    T = BuildTree(a, n, tag);
    if (!Flag){
        cout << "YES" << endl;
        PostPrint(T);
    }
    else cout << "NO" << endl;
    return 0;
}