1389. Create Target Array in the Given Order*

1389. Create Target Array in the Given Order*

​​https://leetcode.com/problems/create-target-array-in-the-given-order/​​

题目描述

Given two arrays of integers ​​num​​​s and ​​index​​. Your task is to create target array under the following rules:

• Initially​​target​​ array is empty.
• From left to right read​​nums[i]​​​ and​​index[i]​​​, insert at index​​index[i]​​​ the value​​nums[i]​​​ in​​target​​ array.
• Repeat the previous step until there are no elements to read in​​nums​​​ and​​index​​.

Return the target array.

It is guaranteed that the insertion operations will be valid.

Example 1:

Input: nums = [0,1,2,3,4], index = [0,1,2,2,1]
Output: [0,4,1,3,2]
Explanation:
nums       index     target
0            0        [0]
1            1        [0,1]
2            2        [0,1,2]
3            2        [0,1,3,2]
4            1        [0,4,1,3,2]

Example 2:

Input: nums = [1,2,3,4,0], index = [0,1,2,3,0]
Output: [0,1,2,3,4]
Explanation:
nums       index     target
1            0        [1]
2            1        [1,2]
3            2        [1,2,3]
4            3        [1,2,3,4]
0            0        [0,1,2,3,4]

Example 3:

Input: nums = [1], index = [0]
Output: [1]

Constraints:

• ​​1 <= nums.length, index.length <= 100​​
• ​​nums.length == index.length​​
• ​​0 <= nums[i] <= 100​​
• ​​0 <= index[i] <= i​​

C++ 实现 1

类似于插入排序的思路.

class Solution {
public:
    vector<int> createTargetArray(vector<int>& nums, vector<int>& index) {
        vector<int> res(nums.size(), 0);
        for (int i = 0; i < nums.size(); ++ i) {
            int idx = index[i];
            int val = nums[i];
            int j = i - 1;
            while (j >= idx) {
                res[j + 1] = res[j];
                -- j;
            }
            res[j + 1] = val;
        }
        return res;
    }
};