2653. Sliding Subarray Beauty

Description

Given an integer array nums containing n integers, find the beauty of each subarray of size k.

The beauty of a subarray is the xth smallest integer in the subarray if it is negative, or 0 if there are fewer than x negative integers.

Return an integer array containing n - k + 1 integers, which denote the beauty of the subarrays in order from the first index in the array.

  • A subarray is a contiguous non-empty sequence of elements within an array.

 

Example 1:

Input: nums = [1,-1,-3,-2,3], k = 3, x = 2
Output: [-1,-2,-2]
Explanation: There are 3 subarrays with size k = 3. 
The first subarray is [1, -1, -3] and the 2nd smallest negative integer is -1. 
The second subarray is [-1, -3, -2] and the 2nd smallest negative integer is -2. 
The third subarray is [-3, -2, 3] and the 2nd smallest negative integer is -2.

Example 2:

Input: nums = [-1,-2,-3,-4,-5], k = 2, x = 2
Output: [-1,-2,-3,-4]
Explanation: There are 4 subarrays with size k = 2.
For [-1, -2], the 2nd smallest negative integer is -1.
For [-2, -3], the 2nd smallest negative integer is -2.
For [-3, -4], the 2nd smallest negative integer is -3.
For [-4, -5], the 2nd smallest negative integer is -4. 

Example 3:

Input: nums = [-3,1,2,-3,0,-3], k = 2, x = 1
Output: [-3,0,-3,-3,-3]
Explanation: There are 5 subarrays with size k = 2.
For [-3, 1], the 1st smallest negative integer is -3.
For [1, 2], there is no negative integer so the beauty is 0.
For [2, -3], the 1st smallest negative integer is -3.
For [-3, 0], the 1st smallest negative integer is -3.
For [0, -3], the 1st smallest negative integer is -3.

 

Constraints:

  • n == nums.length 
  • 1 <= n <= 105
  • 1 <= k <= n
  • 1 <= x <= k 
  • -50 <= nums[i] <= 50 

Solutions

Solution 1

Python Code
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from sortedcontainers import SortedList


class Solution:
    def getSubarrayBeauty(self, nums: List[int], k: int, x: int) -> List[int]:
        sl = SortedList(nums[:k])
        ans = [sl[x - 1] if sl[x - 1] < 0 else 0]
        for i in range(k, len(nums)):
            sl.remove(nums[i - k])
            sl.add(nums[i])
            ans.append(sl[x - 1] if sl[x - 1] < 0 else 0)
        return ans

Java Code
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class Solution {
    public int[] getSubarrayBeauty(int[] nums, int k, int x) {
        int n = nums.length;
        int[] cnt = new int[101];
        for (int i = 0; i < k; ++i) {
            ++cnt[nums[i] + 50];
        }
        int[] ans = new int[n - k + 1];
        ans[0] = f(cnt, x);
        for (int i = k, j = 1; i < n; ++i) {
            ++cnt[nums[i] + 50];
            --cnt[nums[i - k] + 50];
            ans[j++] = f(cnt, x);
        }
        return ans;
    }

    private int f(int[] cnt, int x) {
        int s = 0;
        for (int i = 0; i < 50; ++i) {
            s += cnt[i];
            if (s >= x) {
                return i - 50;
            }
        }
        return 0;
    }
}

C++ Code
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class Solution {
public:
    vector<int> getSubarrayBeauty(vector<int>& nums, int k, int x) {
        int n = nums.size();
        int cnt[101]{};
        for (int i = 0; i < k; ++i) {
            ++cnt[nums[i] + 50];
        }
        vector<int> ans(n - k + 1);
        auto f = [&](int x) {
            int s = 0;
            for (int i = 0; i < 50; ++i) {
                s += cnt[i];
                if (s >= x) {
                    return i - 50;
                }
            }
            return 0;
        };
        ans[0] = f(x);
        for (int i = k, j = 1; i < n; ++i) {
            ++cnt[nums[i] + 50];
            --cnt[nums[i - k] + 50];
            ans[j++] = f(x);
        }
        return ans;
    }
};

Go Code
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func getSubarrayBeauty(nums []int, k int, x int) []int {
	n := len(nums)
	cnt := [101]int{}
	for _, x := range nums[:k] {
		cnt[x+50]++
	}
	ans := make([]int, n-k+1)
	f := func(x int) int {
		s := 0
		for i := 0; i < 50; i++ {
			s += cnt[i]
			if s >= x {
				return i - 50
			}
		}
		return 0
	}
	ans[0] = f(x)
	for i, j := k, 1; i < n; i, j = i+1, j+1 {
		cnt[nums[i]+50]++
		cnt[nums[i-k]+50]--
		ans[j] = f(x)
	}
	return ans
}

TypeScript Code
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function getSubarrayBeauty(nums: number[], k: number, x: number): number[] {
    const n = nums.length;
    const cnt: number[] = new Array(101).fill(0);
    for (let i = 0; i < k; ++i) {
        ++cnt[nums[i] + 50];
    }
    const ans: number[] = new Array(n - k + 1);
    const f = (x: number): number => {
        let s = 0;
        for (let i = 0; i < 50; ++i) {
            s += cnt[i];
            if (s >= x) {
                return i - 50;
            }
        }
        return 0;
    };
    ans[0] = f(x);
    for (let i = k, j = 1; i < n; ++i, ++j) {
        cnt[nums[i] + 50]++;
        cnt[nums[i - k] + 50]--;
        ans[j] = f(x);
    }
    return ans;
}

Solution 2

Python Code
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class Solution:
    def getSubarrayBeauty(self, nums: List[int], k: int, x: int) -> List[int]:
        def f(x: int) -> int:
            s = 0
            for i in range(50):
                s += cnt[i]
                if s >= x:
                    return i - 50
            return 0

        cnt = [0] * 101
        for v in nums[:k]:
            cnt[v + 50] += 1
        ans = [f(x)]
        for i in range(k, len(nums)):
            cnt[nums[i] + 50] += 1
            cnt[nums[i - k] + 50] -= 1
            ans.append(f(x))
        return ans