[leetcode 324] swing sorting II thinking + sorting

Topic link

Given some numbers , Rearrange them to meet ：
< > < > < … Sequence of relationships

Ideas ：
Sort from small to large , Then put the odd digits , Place from left to right, from large to small ; Turn even bits from left to right , Place from large to small , We can get the satisfied result sequence

Code:

class Solution {
    
public:
    void wiggleSort(vector<int>& nums) {
    
        sort(nums.begin(), nums.end());
        int n = nums.size();
        vector<int> v(n);
        int r = n - 1,l = 1;
        for(;l < n;l += 2) {
    
            v[l] = nums[r];
            r --;
        }
        for(l = 0;l < n;l += 2) {
    
            v[l] = nums[r];
            r --;
        }
        nums = v;
    }
};