题解 | #排序#

import java.util.*;

public class Solution {
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 * 将给定数组排序
 * @param arr int整型一维数组 待排序的数组
 * @return int整型一维数组
 */
public int[] MySort (int[] arr) {
    // write code here
    QuickSort(arr,0,arr.length-1);
    return arr;
}
int Partition(int[] arr,int low,int high){
    int pivot=arr[low];
    while(low<high){
        while(low<high&&arr[high]>=pivot)--high;
        arr[low]=arr[high];
        while(low<high&&arr[low]<=pivot)++low;
        arr[high]=arr[low];
    }
    arr[low]=pivot;
    return low;
}

void QuickSort(int[]arr,int low ,int high){
    if(low<high){
        int pivotpos=Partition(arr,low,high);
        QuickSort(arr,low,pivotpos-1);
        QuickSort(arr,pivotpos+1,high);
    }
}
import java.util.*;

public class Solution { /** * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可 * 将给定数组排序 * @param arr int整型一维数组 待排序的数组 * @return int整型一维数组 */

public int[] MySort (int[] arr) {
    // write code here
   MergeSort(arr,0,arr.length-1);
   return arr;
}
void Merge(int[] arr,int low,int mid,int high){
    int[] help=new int[high-low+1];
    int i=0;
    int p=low;
    int q=mid+1;
    while(p<=mid&&q<=high){
        help[i++]=arr[p]<arr[q]? arr[p++]:arr[q++];
    }
    while(p<=mid)
        help[i++]=arr[p++];
    while(q<=high)
        help[i++]=arr[q++];
    for(i=0;i<help.length;i++){
        arr[low+i]=help[i];
    }
}

void MergeSort(int[] arr,int low,int high){ if(low<high){ int mid=(low+high)>>1; MergeSort(arr,low,mid); MergeSort(arr,mid+1,high); Merge(arr,low,mid,high); } }

}import java.util.*;

public class Solution { /** * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可 * 将给定数组排序 * @param arr int整型一维数组 待排序的数组 * @return int整型一维数组 */

public int[] MySort (int[] arr) {
    // write code here
   MergeSort(arr,0,arr.length-1);
   return arr;
}
void Merge(int[] arr,int low,int mid,int high){
    int[] help=new int[high-low+1];
    int i=0;
    int p=low;
    int q=mid+1;
    while(p<=mid&&q<=high){
        help[i++]=arr[p]<arr[q]? arr[p++]:arr[q++];
    }
    while(p<=mid)
        help[i++]=arr[p++];
    while(q<=high)
        help[i++]=arr[q++];
    for(i=0;i<help.length;i++){
        arr[low+i]=help[i];
    }
}

void MergeSort(int[] arr,int low,int high){ if(low<high){ int mid=(low+high)>>1; MergeSort(arr,low,mid); MergeSort(arr,mid+1,high); Merge(arr,low,mid,high); } }

} }