希尔排序

希尔排序的时间复杂度,最好的情况下仍然是正序时,可达到O(n),平均复杂度为O(nlogn)。

算法思想:

  采用跳跃式处理数组,使得数组粗粒度的实现基本有序。在进行细粒度的处理,最终使得网络在跳越数为1时,实现基本有序的排序,以减少插入排序的复杂度。

主要程序:

void shellSort(int *arr,int length){
    int i,j,k;
    int increment = length;
    while(increment>0){
        if(increment != 1)
            increment = increment/3+1;
        else
            break;
        for(i = increment; i<length; i++){
            if(arr[i] < arr[i-increment]){
                k = arr[i];
                for(j=i-increment; j>=0 && k < arr[j] ; j-=increment){
                    arr[j+increment] = arr[j];
                }
                arr[j+increment] = k;
            }
        }
    }
}

全部代码:

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int arrtest1[10] = {3,4,7,8,0,9,1,2,6,5};
int arrtest2[10] = {0,1,2,3,4,5,6,7,8,9};
int arrtest3[10] = {9,8,7,6,5,4,3,2,1,0};
void copy(int *from,int *arr,int length);
void print(int *arr,int length);
void shellSort(int *arr,int length);
int main(){
    clock_t start,end;
    int Arr[10];
    int i;
    copy(arrtest1,Arr,10);
    print(Arr,10);
    shellSort(Arr,10);
    print(Arr,10);
    start = clock();
    for(i=0;i<100000;i++){
        copy(arrtest1,Arr,10);
        //print(Arr,10);
        shellSort(Arr,10);
        //print(Arr,10);
    }
    end = clock();
    printf("first test:%d\n",end-start);

    start = clock();
    for(i=0;i<100000;i++){
        copy(arrtest2,Arr,10);
        //print(Arr,10);
        shellSort(Arr,10);
        //print(Arr,10);
    }
    end = clock();
    printf("first test:%d\n",end-start);

    start = clock();
    for(i=0;i<100000;i++){
        copy(arrtest3,Arr,10);
        //print(Arr,10);
        shellSort(Arr,10);
        //print(Arr,10);
    }
    end = clock();
    printf("first test:%d\n",end-start);
    
    getchar();
    return 0;
}
void shellSort(int *arr,int length){
    int i,j,k;
    int increment = length;
    while(increment>0){
        if(increment != 1)
            increment = increment/3+1;
        else
            break;
        for(i = increment; i<length; i++){
            if(arr[i] < arr[i-increment]){
                k = arr[i];
                for(j=i-increment; j>=0 && k < arr[j] ; j-=increment){
                    arr[j+increment] = arr[j];
                }
                arr[j+increment] = k;
            }
        }
    }
}
void copy(int *from,int *arr,int length){
    int i;
    for(i=0;i<length;i++){
        arr[i] = from[i];
    }
}

void print(int *arr,int length){
    int i;
    for(i=0;i<length;i++){
        printf("%d ",arr[i]);
    }
    printf("\n");
}
View Code

运行示例:

posted @ 2014-04-14 15:03  xingoo  阅读(572)  评论(0编辑  收藏  举报