Codeforces Round 149 (Div. 2)
C
King's Path
Codeforces
1800
原题
← BD →
翻译中…

The black king is standing on a chess field consisting of $10^{9}$ rows and $10^{9}$ columns. We will consider the rows of the field numbered with integers from $1$ to $10^{9}$ from top to bottom. The columns are similarly numbered with integers from $1$ to $10^{9}$ from left to right. We will denote a cell of the field that is located in the $*i*$-th row and $*j*$-th column as $(*i*, *j*)$.

翻译中…

You know that some squares of the given chess field are allowed. All allowed cells of the chess field are given as $*n*$ segments. Each segment is described by three integers $*r*_{*i*}, *a*_{*i*}, *b*_{*i*}$ $(*a*_{*i*} ≤ *b*_{*i*})$, denoting that cells in columns from number $*a*_{*i*}$ to number $*b*_{*i*}$ inclusive in the $*r*_{*i*}$-th row are allowed.

翻译中…

Your task is to find the minimum number of moves the king needs to get from square $(*x*_{0}, *y*_{0})$ to square $(*x*_{1}, *y*_{1})$, provided that he only moves along the allowed cells. In other words, the king can be located only on allowed cells on his way.

翻译中…

Let us remind you that a chess king can move to any of the neighboring cells in one move. Two cells of a chess field are considered neighboring if they share at least one point.

翻译中…

Input

翻译中…

The first line contains four space-separated integers $*x*_{0}, *y*_{0}, *x*_{1}, *y*_{1}$ $(1 ≤ *x*_{0}, *y*_{0}, *x*_{1}, *y*_{1} ≤ 10^{9})$, denoting the initial and the final positions of the king.

翻译中…

The second line contains a single integer $*n*$ $(1 ≤ *n* ≤ 10^{5})$, denoting the number of segments of allowed cells. Next $*n*$ lines contain the descriptions of these segments. The $*i*$-th line contains three space-separated integers $*r*_{*i*}, *a*_{*i*}, *b*_{*i*}$ $(1 ≤ *r*_{*i*}, *a*_{*i*}, *b*_{*i*} ≤ 10^{9}, *a*_{*i*} ≤ *b*_{*i*})$, denoting that cells in columns from number $*a*_{*i*}$ to number $*b*_{*i*}$ inclusive in the $*r*_{*i*}$-th row are allowed. Note that the segments of the allowed cells can intersect and embed arbitrarily.

翻译中…

It is guaranteed that the king's initial and final position are allowed cells. It is guaranteed that the king's initial and the final positions do not coincide. It is guaranteed that the total length of all given segments doesn't exceed $10^{5}$.

翻译中…

Output

翻译中…

If there is no path between the initial and final position along allowed cells, print -1.

翻译中…

Otherwise print a single integer — the minimum number of moves the king needs to get from the initial position to the final one.

翻译中…

样例

Input #1
5 7 6 11
3
5 3 8
6 7 11
5 2 5
Output #1
4
InputCopy OutputCopy
Input #2
3 4 3 10
3
3 1 4
4 5 9
3 10 10
Output #2
6
InputCopy OutputCopy
Input #3
1 1 2 10
2
1 1 3
2 6 10
Output #3
-1
InputCopy OutputCopy
题目信息
题号
242C
时间限制
2 s
内存限制
256 MB
标签
DFS 及类似
图论
哈希
最短路

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。