leetcode(8)

leetcode(8)

667. Beautiful Arrangement II

Given two integers n and k, you need to construct a list which contains n different positive integers ranging from 1 to n and obeys the following requirement:
Suppose this list is [a1, a2, a3, … , an], then the list [|a1 – a2|, |a2 – a3|, |a3 – a4|, … , |an-1 – an|] has exactly k distinct integers.

If there are multiple answers, print any of them.

Example 1:

Input: n = 3, k = 1
Output: [1, 2, 3]
Explanation: The [1, 2, 3] has three different positive integers ranging from 1 to 3, and the [1, 1] has exactly 1 distinct integer: 1.

Example 2:

Input: n = 3, k = 2
Output: [1, 3, 2]
Explanation: The [1, 3, 2] has three different positive integers ranging from 1 to 3, and the [2, 1] has exactly 2 distinct integers: 1 and 2.

Note:

  1. The n and k are in the range 1 <= k < n <= 104.

class Solution {
public:
vector<int> constructArray(int n, int k) {
vector<int> res;
int j=n;

//找一个规律,首尾交叉插入来获得不同的distinct intergers

//eg:    1 7 2 6 3 5 4     max:n-1    需要获得多少个,用k来控制

//eg:k=2    7 1 2 3 4 5 6        k=4    7 1 6 2 3 4 5

//eg:k=3    1 7 2 3 4 5 6        k=5    1 7 2 6 3 4 5 ....  
//maybe you find the rule

for(int i=1;i<=j;)
if(k>1)
{
res.push_back(k--%2?i++:j--);
}else
{
res.push_back(i++);
}
return res;
}
};




So BadJust So SoGoodCoolPretty Cool (还没人评过分呢!)
Loading...

发表评论

电子邮件地址不会被公开。 必填项已用*标注