A9745. Strip
编程题
普及/提高-
知识点
题目描述
Alexandra has a paper strip with $n$ numbers on it. Let's call them $a_{i}$ from left to right.
Now Alexandra wants to split it into some pieces (possibly $1$ ). For each piece of strip, it must satisfy:
- Each piece should contain at least $l$ numbers.
- The difference between the maximal and the minimal number on the piece should be at most $s$ .
Please help Alexandra to find the minimal number of pieces meeting the condition above.
Now Alexandra wants to split it into some pieces (possibly $1$ ). For each piece of strip, it must satisfy:
- Each piece should contain at least $l$ numbers.
- The difference between the maximal and the minimal number on the piece should be at most $s$ .
Please help Alexandra to find the minimal number of pieces meeting the condition above.
输入格式
Alexandra has a paper strip with $n$ numbers on it. Let's call them $a_{i}$ from left to right.
Now Alexandra wants to split it into some pieces (possibly $1$ ). For each piece of strip, it must satisfy:
- Each piece should contain at least $l$ numbers.
- The difference between the maximal and the minimal number on the piece should be at most $s$ .
Please help Alexandra to find the minimal number of pieces meeting the condition above.
Now Alexandra wants to split it into some pieces (possibly $1$ ). For each piece of strip, it must satisfy:
- Each piece should contain at least $l$ numbers.
- The difference between the maximal and the minimal number on the piece should be at most $s$ .
Please help Alexandra to find the minimal number of pieces meeting the condition above.
输出格式
Output the minimal number of strip pieces.
If there are no ways to split the strip, output -1.
If there are no ways to split the strip, output -1.
输入输出样例
输入 #1
7 2 2 1 3 1 2 4 1 2
输出 #1
3
输入 #2
7 2 2 1 100 1 100 1 100 1
输出 #2
-1
说明/提示
Alexandra has a paper strip with $n$ numbers on it. Let's call them $a_{i}$ from left to right.
Now Alexandra wants to split it into some pieces (possibly $1$ ). For each piece of strip, it must satisfy:
- Each piece should contain at least $l$ numbers.
- The difference between the maximal and the minimal number on the piece should be at most $s$ .
Please help Alexandra to find the minimal number of pieces meeting the condition above.
Now Alexandra wants to split it into some pieces (possibly $1$ ). For each piece of strip, it must satisfy:
- Each piece should contain at least $l$ numbers.
- The difference between the maximal and the minimal number on the piece should be at most $s$ .
Please help Alexandra to find the minimal number of pieces meeting the condition above.