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剑指 Offer II 075. 数组相对排序

题目描述

给定两个数组，arr1 和 arr2，

  • arr2 中的元素各不相同
  • arr2 中的每个元素都出现在 arr1 中

对 arr1 中的元素进行排序，使 arr1 中项的相对顺序和 arr2 中的相对顺序相同。未在 arr2 中出现过的元素需要按照升序放在 arr1 的末尾。

 

示例：

输入：arr1 = [2,3,1,3,2,4,6,7,9,2,19], arr2 = [2,1,4,3,9,6]
输出：[2,2,2,1,4,3,3,9,6,7,19]

 

提示：

  • 1 <= arr1.length, arr2.length <= 1000
  • 0 <= arr1[i], arr2[i] <= 1000
  • arr2 中的元素 arr2[i] 各不相同
  • arr2 中的每个元素 arr2[i] 都出现在 arr1 中

 

注意：本题与主站 1122 题相同：https://leetcode.cn/problems/relative-sort-array/ 

解法

方法一

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class Solution:
    def relativeSortArray(self, arr1: List[int], arr2: List[int]) -> List[int]:
        mp = {num: i for i, num in enumerate(arr2)}
        arr1.sort(key=lambda x: (mp.get(x, 10000), x))
        return arr1

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class Solution {
    public int[] relativeSortArray(int[] arr1, int[] arr2) {
        int[] mp = new int[1001];
        for (int x : arr1) {
            ++mp[x];
        }
        int i = 0;
        for (int x : arr2) {
            while (mp[x]-- > 0) {
                arr1[i++] = x;
            }
        }
        for (int j = 0; j < mp.length; ++j) {
            while (mp[j]-- > 0) {
                arr1[i++] = j;
            }
        }
        return arr1;
    }
}

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class Solution {
public:
    vector<int> relativeSortArray(vector<int>& arr1, vector<int>& arr2) {
        vector<int> mp(1001);
        for (int x : arr1) ++mp[x];
        int i = 0;
        for (int x : arr2) {
            while (mp[x]-- > 0) arr1[i++] = x;
        }
        for (int j = 0; j < mp.size(); ++j) {
            while (mp[j]-- > 0) arr1[i++] = j;
        }
        return arr1;
    }
};

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func relativeSortArray(arr1 []int, arr2 []int) []int {
    mp := make([]int, 1001)
    for _, x := range arr1 {
        mp[x]++
    }
    i := 0
    for _, x := range arr2 {
        for mp[x] > 0 {
            arr1[i] = x
            mp[x]--
            i++
        }
    }
    for j, cnt := range mp {
        for cnt > 0 {
            arr1[i] = j
            i++
            cnt--
        }
    }
    return arr1
}

方法二

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class Solution:
    def relativeSortArray(self, arr1: List[int], arr2: List[int]) -> List[int]:
        mp = [0] * 1001
        for x in arr1:
            mp[x] += 1
        i = 0
        for x in arr2:
            while mp[x] > 0:
                arr1[i] = x
                mp[x] -= 1
                i += 1
        for x, cnt in enumerate(mp):
            for _ in range(cnt):
                arr1[i] = x
                i += 1
        return arr1

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