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263 lines (227 loc) · 6.84 KB
comments difficulty edit_url rating source tags
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中等
2011
第 82 场双周赛 Q3
数组
数学
排序
堆(优先队列)

English Version

题目描述

给你两个下标从 0 开始的整数数组 nums1 和 nums2 ,长度为 n 。

数组 nums1 和 nums2 的 差值平方和 定义为所有满足 0 <= i < n 的 (nums1[i] - nums2[i])2 之和。

同时给你两个正整数 k1 和 k2 。你可以将 nums1 中的任意元素 +1 或者 -1 至多 k1 次。类似的,你可以将 nums2 中的任意元素 +1 或者 -1 至多 k2 次。

请你返回修改数组 nums1 至多 k1 次且修改数组 nums2 至多 k2 次后的最小 差值平方和 。

注意:你可以将数组中的元素变成  整数。

 

示例 1:

输入:nums1 = [1,2,3,4], nums2 = [2,10,20,19], k1 = 0, k2 = 0
输出:579
解释:nums1 和 nums2 中的元素不能修改,因为 k1 = 0 和 k2 = 0 。
差值平方和为:(1 - 2)2 + (2 - 10)2 + (3 - 20)2 + (4 - 19)2 = 579 。

示例 2:

输入:nums1 = [1,4,10,12], nums2 = [5,8,6,9], k1 = 1, k2 = 1
输出:43
解释:一种得到最小差值平方和的方式为:
- 将 nums1[0] 增加一次。
- 将 nums2[2] 增加一次。
最小差值平方和为:
(2 - 5)2 + (4 - 8)2 + (10 - 7)2 + (12 - 9)2 = 43 。
注意,也有其他方式可以得到最小差值平方和,但没有得到比 43 更小答案的方案。

 

提示:

  • n == nums1.length == nums2.length
  • 1 <= n <= 105
  • 0 <= nums1[i], nums2[i] <= 105
  • 0 <= k1, k2 <= 109

解法

方法一:二分查找

Python3

class Solution:
    def minSumSquareDiff(
        self, nums1: List[int], nums2: List[int], k1: int, k2: int
    ) -> int:
        d = [abs(a - b) for a, b in zip(nums1, nums2)]
        k = k1 + k2
        if sum(d) <= k:
            return 0
        left, right = 0, max(d)
        while left < right:
            mid = (left + right) >> 1
            if sum(max(v - mid, 0) for v in d) <= k:
                right = mid
            else:
                left = mid + 1
        for i, v in enumerate(d):
            d[i] = min(left, v)
            k -= max(0, v - left)
        for i, v in enumerate(d):
            if k == 0:
                break
            if v == left:
                k -= 1
                d[i] -= 1
        return sum(v * v for v in d)

Java

class Solution {
    public long minSumSquareDiff(int[] nums1, int[] nums2, int k1, int k2) {
        int n = nums1.length;
        int[] d = new int[n];
        long s = 0;
        int mx = 0;
        int k = k1 + k2;
        for (int i = 0; i < n; ++i) {
            d[i] = Math.abs(nums1[i] - nums2[i]);
            s += d[i];
            mx = Math.max(mx, d[i]);
        }
        if (s <= k) {
            return 0;
        }
        int left = 0, right = mx;
        while (left < right) {
            int mid = (left + right) >> 1;
            long t = 0;
            for (int v : d) {
                t += Math.max(v - mid, 0);
            }
            if (t <= k) {
                right = mid;
            } else {
                left = mid + 1;
            }
        }
        for (int i = 0; i < n; ++i) {
            k -= Math.max(0, d[i] - left);
            d[i] = Math.min(d[i], left);
        }
        for (int i = 0; i < n && k > 0; ++i) {
            if (d[i] == left) {
                --k;
                --d[i];
            }
        }
        long ans = 0;
        for (int v : d) {
            ans += (long) v * v;
        }
        return ans;
    }
}

C++

using ll = long long;

class Solution {
public:
    long long minSumSquareDiff(vector<int>& nums1, vector<int>& nums2, int k1, int k2) {
        int n = nums1.size();
        vector<int> d(n);
        ll s = 0;
        int mx = 0;
        int k = k1 + k2;
        for (int i = 0; i < n; ++i) {
            d[i] = abs(nums1[i] - nums2[i]);
            s += d[i];
            mx = max(mx, d[i]);
        }
        if (s <= k) return 0;
        int left = 0, right = mx;
        while (left < right) {
            int mid = (left + right) >> 1;
            ll t = 0;
            for (int v : d) t += max(v - mid, 0);
            if (t <= k)
                right = mid;
            else
                left = mid + 1;
        }
        for (int i = 0; i < n; ++i) {
            k -= max(0, d[i] - left);
            d[i] = min(d[i], left);
        }
        for (int i = 0; i < n && k; ++i) {
            if (d[i] == left) {
                --k;
                --d[i];
            }
        }
        ll ans = 0;
        for (int v : d) ans += 1ll * v * v;
        return ans;
    }
};

Go

func minSumSquareDiff(nums1 []int, nums2 []int, k1 int, k2 int) int64 {
	k := k1 + k2
	s, mx := 0, 0
	n := len(nums1)
	d := make([]int, n)
	for i, v := range nums1 {
		d[i] = abs(v - nums2[i])
		s += d[i]
		mx = max(mx, d[i])
	}
	if s <= k {
		return 0
	}
	left, right := 0, mx
	for left < right {
		mid := (left + right) >> 1
		t := 0
		for _, v := range d {
			t += max(v-mid, 0)
		}
		if t <= k {
			right = mid
		} else {
			left = mid + 1
		}
	}
	for i, v := range d {
		k -= max(v-left, 0)
		d[i] = min(v, left)
	}
	for i, v := range d {
		if k <= 0 {
			break
		}
		if v == left {
			d[i]--
			k--
		}
	}
	ans := 0
	for _, v := range d {
		ans += v * v
	}
	return int64(ans)
}

func abs(x int) int {
	if x < 0 {
		return -x
	}
	return x
}