codeforces#P1932G. Moving Platforms
Moving Platforms
Description
There is a game where you need to move through a labyrinth. The labyrinth consists of $n$ platforms, connected by $m$ passages.
Each platform is at some level $l_i$, an integer number from $0$ to $H - 1$. In a single step, if you are currently on platform $i$, you can stay on it, or move to another platform $j$. To move to platform $j$ they have to be connected by the passage, and their levels have to be the same, namely $l_i = l_j$.
After each step, the levels of all platforms change. The new level of platform $i$ is calculated as $l'_i = (l_i + s_i) \bmod H$, for all $i$.
You start on platform $1$. Find the minimum number of steps you need to get to platform $n$.
The first line of input contains a single integer $t$ ($1 \le t \le 10^4$) — the number of test cases. Then the descriptions of the test cases follow.
The first line of each test case contains three integers $n$, $m$, and $H$ ($2 \le n \le 10^5$, $1 \le m \le 10^5$, $1 \le H \le 10^9$).
The second line contains $n$ integers $l_i$, the initial level of each platform ($0 \le l_i \le H-1$).
The third line contains $n$ integers $s_i$, the change of level for each platform ($0 \le s_i \le H-1$).
Next $m$ lines contain a description of the passages. Each passage is described as a pair of integers — the platforms, connected by the passage. There is at most one passage connecting each pair of platforms, and there is no passage connecting a platform to itself.
The sum of $n$ for all tests does not exceed $10^5$, the sum of $m$ for all tests does not exceed $10^5$.
For each test case, print a single integer, the minimum number of steps needed to get from platform $1$ to platform $n$.
If it is impossible to get to platform $n$, print $-1$.
Input
The first line of input contains a single integer $t$ ($1 \le t \le 10^4$) — the number of test cases. Then the descriptions of the test cases follow.
The first line of each test case contains three integers $n$, $m$, and $H$ ($2 \le n \le 10^5$, $1 \le m \le 10^5$, $1 \le H \le 10^9$).
The second line contains $n$ integers $l_i$, the initial level of each platform ($0 \le l_i \le H-1$).
The third line contains $n$ integers $s_i$, the change of level for each platform ($0 \le s_i \le H-1$).
Next $m$ lines contain a description of the passages. Each passage is described as a pair of integers — the platforms, connected by the passage. There is at most one passage connecting each pair of platforms, and there is no passage connecting a platform to itself.
The sum of $n$ for all tests does not exceed $10^5$, the sum of $m$ for all tests does not exceed $10^5$.
Output
For each test case, print a single integer, the minimum number of steps needed to get from platform $1$ to platform $n$.
If it is impossible to get to platform $n$, print $-1$.
3
3 3 10
1 9 4
2 3 0
1 2
3 2
1 3
2 1 10
1 2
4 6
1 2
8 7 25
22 14 5 3 10 14 11 1
9 5 4 10 7 16 18 18
2 8
6 3
3 5
7 5
2 6
1 4
4 7
6
-1
52
Note
This is how levels of the platforms change, and what actions we need to perform in the first example.
| Platform 1 | Platform 2 | Platform 3 | Action | |
| Step 1 | 1 | 9 | 4 | Stay on the platform 1 |
| Step 2 | 3 | 2 | 4 | Stay on the platform 1 |
| Step 3 | 5 | 5 | 4 | Move to the platform 2 |
| Step 4 | 7 | 8 | 4 | Stay on the platform 2 |
| Step 5 | 9 | 1 | 4 | Stay on the platform 2 |
| Step 6 | 1 | 4 | 4 | Move to the platform 3 |