992. Sort Array By Parity II - LeetCode

Question

992. Sort Array By Parity II

Solution

題目大意：給一個int數組，一半是奇數一半是偶數，分別對偶數數和奇數數排序並要求這個數自己是偶數要放在偶數位上

思路：把奇數數和偶數數篩選出來後對其分別排序，再按奇偶索引放到原數組上

Java實現：

public int[] sortArrayByParityII(int[] A) {
    List<Integer> oddList = new ArrayList<>();
    List<Integer> evenList = new ArrayList<>();
    for (int a : A) {
        if (a % 2 == 0) evenList.add(a);
        else oddList.add(a);
    }
    Collections.sort(oddList);
    Collections.sort(evenList);
    for (int i = 0; i < oddList.size(); i++) {
        A[2 * i] = evenList.get(i);
        A[2 * i + 1] = oddList.get(i);
    }
    return A;
}