C语言 | Leetcode C语言题解之第368题最大整除子集

题目：

题解：

int cmp(int* a, int* b) {return *a - *b;
}int* largestDivisibleSubset(int* nums, int numsSize, int* returnSize) {int len = numsSize;qsort(nums, numsSize, sizeof(int), cmp);// 第 1 步：动态规划找出最大子集的个数、最大子集中的最大整数int dp[len];for (int i = 0; i < len; i++) {dp[i] = 1;}int maxSize = 1;int maxVal = dp[0];for (int i = 1; i < len; i++) {for (int j = 0; j < i; j++) {// 题目中说「没有重复元素」很重要if (nums[i] % nums[j] == 0) {dp[i] = fmax(dp[i], dp[j] + 1);}}if (dp[i] > maxSize) {maxSize = dp[i];maxVal = nums[i];}}// 第 2 步：倒推获得最大子集int* res = malloc(sizeof(int) * len);*returnSize = 0;if (maxSize == 1) {res[(*returnSize)++] = nums[0];return res;}for (int i = len - 1; i >= 0 && maxSize > 0; i--) {if (dp[i] == maxSize && maxVal % nums[i] == 0) {res[(*returnSize)++] = nums[i];maxVal = nums[i];maxSize--;}}return res;
}