STREETR - Street Trees
A group of trees is planted along a straight line. KOI is planning to plant more trees so that the distance between two adjacent trees is equal for all trees. For simplicity, each tree can only be planted on an integer coordinate.
For example, if 4 trees were originally planted on coordinates (1, 3, 7, 13), and if KOI plants 3 more trees on coordinates (5, 9, 11), then the distance between two adjacent trees will equal for all trees.
Your task is to calculate the minimal number of trees that KOI can plant so that the distance between two adjacent trees will equal for all trees.
Input
The first line is an integer N (3 <= N <= 100,000), which denotes the number of already planted trees.
The next N lines will have an integer X (1 <= X <= 1,000,000,000), which denotes the coordinate of each tree.
You can safely assume that the value of X will be unique.
Output
Output the minimal number of trees that must be planted.
Example
Input: 4 1 3 7 13 Output: 3
Input: 4 2 6 12 18 Output: 5
[Edited] Warning: Some input file contains garbage at the end.
hide comments
saket diwakar:
2013-01-16 11:15:45
got AC using python....
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:D:
2012-12-10 21:41:52
I will help you understand this judge :)
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strings:
2012-12-10 20:48:43
seriously... sometimes i am not able to understand this judge.
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Simón Murillo Gómez:
2012-07-25 04:28:58
Easy one. by the way, no need to sort and answer will fit in int |
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Darky:
2012-06-19 17:29:03
fooh..finally! BTW, no need to sort! |
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[ !0 ]:
2011-10-28 12:44:08
Yes, coordinates are in ascending order. No need to sort them. |
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zayin:
2011-10-20 02:53:16
why is the answer 3 for testcase 5, 9, 11 (on the description). shouldn't it be 1 ? Last edit: 2011-10-20 02:56:31 |
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:D:
2011-10-08 07:44:31
If the description doesn't say anything about the order, don't assume it's sorted I already wrote that below, read other comments before posting questions.
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sri:
2011-10-06 20:19:47
are the co ordinates given in sorted order??
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sudipto das:
2011-03-22 07:50:34
are coordinates given in increasing order?
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Added by: | Lawl |
Date: | 2011-01-05 |
Time limit: | 0.203s-1s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: ASM64 |
Resource: | 2010 KOI High School Division |