1054. Distant Barcodes

Description

In a warehouse, there is a row of barcodes, where the ith barcode is barcodes[i].

Rearrange the barcodes so that no two adjacent barcodes are equal. You may return any answer, and it is guaranteed an answer exists.

 

Example 1:

Input: barcodes = [1,1,1,2,2,2]
Output: [2,1,2,1,2,1]

Example 2:

Input: barcodes = [1,1,1,1,2,2,3,3]
Output: [1,3,1,3,1,2,1,2]

 

Constraints:

  • 1 <= barcodes.length <= 10000
  • 1 <= barcodes[i] <= 10000

Solutions

Solution 1

Python Code
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class Solution:
    def rearrangeBarcodes(self, barcodes: List[int]) -> List[int]:
        cnt = Counter(barcodes)
        barcodes.sort(key=lambda x: (-cnt[x], x))
        n = len(barcodes)
        ans = [0] * len(barcodes)
        ans[::2] = barcodes[: (n + 1) // 2]
        ans[1::2] = barcodes[(n + 1) // 2 :]
        return ans

Java Code
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class Solution {
    public int[] rearrangeBarcodes(int[] barcodes) {
        int n = barcodes.length;
        Integer[] t = new Integer[n];
        int mx = 0;
        for (int i = 0; i < n; ++i) {
            t[i] = barcodes[i];
            mx = Math.max(mx, barcodes[i]);
        }
        int[] cnt = new int[mx + 1];
        for (int x : barcodes) {
            ++cnt[x];
        }
        Arrays.sort(t, (a, b) -> cnt[a] == cnt[b] ? a - b : cnt[b] - cnt[a]);
        int[] ans = new int[n];
        for (int k = 0, j = 0; k < 2; ++k) {
            for (int i = k; i < n; i += 2) {
                ans[i] = t[j++];
            }
        }
        return ans;
    }
}

C++ Code
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class Solution {
public:
    vector<int> rearrangeBarcodes(vector<int>& barcodes) {
        int mx = *max_element(barcodes.begin(), barcodes.end());
        int cnt[mx + 1];
        memset(cnt, 0, sizeof(cnt));
        for (int x : barcodes) {
            ++cnt[x];
        }
        sort(barcodes.begin(), barcodes.end(), [&](int a, int b) {
            return cnt[a] > cnt[b] || (cnt[a] == cnt[b] && a < b);
        });
        int n = barcodes.size();
        vector<int> ans(n);
        for (int k = 0, j = 0; k < 2; ++k) {
            for (int i = k; i < n; i += 2) {
                ans[i] = barcodes[j++];
            }
        }
        return ans;
    }
};

Go Code
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func rearrangeBarcodes(barcodes []int) []int {
	mx := slices.Max(barcodes)
	cnt := make([]int, mx+1)
	for _, x := range barcodes {
		cnt[x]++
	}
	sort.Slice(barcodes, func(i, j int) bool {
		a, b := barcodes[i], barcodes[j]
		if cnt[a] == cnt[b] {
			return a < b
		}
		return cnt[a] > cnt[b]
	})
	n := len(barcodes)
	ans := make([]int, n)
	for k, j := 0, 0; k < 2; k++ {
		for i := k; i < n; i, j = i+2, j+1 {
			ans[i] = barcodes[j]
		}
	}
	return ans
}

TypeScript Code
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function rearrangeBarcodes(barcodes: number[]): number[] {
    const mx = Math.max(...barcodes);
    const cnt = Array(mx + 1).fill(0);
    for (const x of barcodes) {
        ++cnt[x];
    }
    barcodes.sort((a, b) => (cnt[a] === cnt[b] ? a - b : cnt[b] - cnt[a]));
    const n = barcodes.length;
    const ans = Array(n);
    for (let k = 0, j = 0; k < 2; ++k) {
        for (let i = k; i < n; i += 2, ++j) {
            ans[i] = barcodes[j];
        }
    }
    return ans;
}