【LeetCode刷题】912. 排序数组

912. 排序数组(点击跳转LeetCode)

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]

题解

语言：C++

思路：归并排序

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