Leetcode 922. Sort Array By Parity II
阿新 • • 發佈:2019-01-03
題目
連結:https://leetcode.com/problems/sort-array-by-parity-ii/
Level: Easy
Discription:
Given an array A of non-negative integers, half of the integers in A are odd, and half of the integers are even.
Sort the array so that whenever A[i] is odd, i is odd; and whenever A[i] is even, i is even.
You may return any answer array that satisfies this condition.
Example 1:
Input: [4,2,5,7]
Output: [4,5,2,7]
Explanation: [4,7,2,5], [2,5,4,7], [2,7,4,5] would also have been accepted.
Note:
- 2 <= A.length <= 20000
- A.length % 2 == 0
- 0 <= A[i] <= 1000
程式碼
class Solution { public: vector<int> sortArrayByParityII(vector<int>& A) { int index0=1; int index1=0; while(index0<A.size() && index1<A.size()) { if(!(A[index0]%2==0)) { index0+=2; continue; } if(!(A[index1]%2==1)) { index1+=2; continue; } swap(A[index0],A[index1]); index0+=2; index1+=2; } return A; } };
思考
- 演算法時間複雜度為O(N),空間複雜度為O(1)。
- 雙指標