Leetcode-912-排序数组(快排,归并)

原题链接
给你一个整数数组 nums，请你将该数组升序排列。
示例 1：

输入：nums = [5,2,3,1]
输出：[1,2,3,5]
示例 2：

输入：nums = [5,1,1,2,0,0]
输出：[0,0,1,1,2,5]

提示：

1 <= nums.length <= 50000
-50000 <= nums[i] <= 50000

来源：力扣（LeetCode）

快排模板的运用

class Solution {
public:
    vector<int> sortArray(vector<int>& nums) {
        int n = nums.size();
       quick_sort(nums,0,n-1);
       return nums;
    }

    void quick_sort(vector<int> &q ,int l,int r){
        if(l>=r) return;
        int x = q[(l+r) >> 1],i  = l-1, j=r+1;
        while(i<j){
            do{
                i++;
            }while(q[i]<x);
            
            do{
                j--;
            }while(q[j]>x);
            if(i<j) swap(q[i],q[j]);
        }
        quick_sort(q,l,j);
        quick_sort(q,j+1,r);
    }
};

归并模板的应用

class Solution {
    vector<int> temp;
        void merge_sort(vector<int>& q ,int l,int r){
        if(l>=r) return;
        int mid = (l+r) >> 1;
        merge_sort(q,l,mid);
        merge_sort(q,mid+1,r);
        int k = 0 , i = l , j = mid+1;
        while(i <= mid && j <= r){
            if(q[i] < q[j]) temp[k++] = q[i++];
            else temp[k++] = q[j++];
        }
        while(i <= mid) temp[k++] = q[i++];
        while(j <= r) temp[k++] = q[j++];
        for(i = l , j = 0 ; i <= r ; i++ , j++ ) q[i] = temp[j];
    }
public:
    vector<int> sortArray(vector<int>& nums) {
        int n = nums.size();
        temp.resize(n,0);
        merge_sort(nums,0,n-1);
       return nums;
    }
};

STL sort

class Solution {
public:
    vector<int> sortArray(vector<int>& nums) {
        sort(nums.begin(),nums.end());
        return nums;
    }
};