LeetCode六月挑战(6.13)Largest Divisible Subset Solution解题方案
Largest Divisible Subset
Solution
Given a set of distinct positive integers, find the largest subset such that every pair (Si, Sj) of elements in this subset satisfies:
Si % Sj = 0 or Sj % Si = 0.
If there are multiple solutions, return any subset is fine.
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| Example 1:
Input: [1,2,3]
Output: [1,2] (of course, [1,3] will also be ok)
Example 2:
Input: [1,2,4,8]
Output: [1,2,4,8]
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思路
这道题有一个数学思路在里面
对于一个有序数组，插入的数如果能整除数组中最大的数，那么也可以整除数组中其他的数。
因此我们要先将数组排序，然后设置一个路径储存数组记录添加元素的路径。
Java代码
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| class Solution {
public List<Integer> largestDivisibleSubset(int[] nums) {
int n = nums.length;
Arrays.sort(nums);
int[] count = new int[n];
int[] road = new int[n];
int max = 0, index = -1;
for (int i = 0; i < n; i++) {
count[i] = 1;
road[i] = -1;
for (int j = i - 1; j >= 0; j--) {
if (nums[i] % nums[j] == 0) {
if (count[i] < 1 + count[j]) {
count[i] = count[j] + 1;
road[i] = j;
}
}
}
if (count[i] > max) {
max = count[i];
index = i;
}
}
List<Integer> result = new ArrayList<>();
while (index != -1) {
result.add(nums[index]);
index = road[index];
}
return result;
}
}
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