2015年大二上-数据结构-内部排序-(7)-归并排序

/*
*Copyright (c) 2014,烟台大学计算机学院
*All rights reserved.
*文件名称:Annpion.cpp
*作者:王耀鹏
*完成日期:2016年3月30日
*版本号:v1.0
*
*问题描述:归并排序
*输入描述:待排序数组
*输出描述:归并排序
*/
#include <stdio.h>
#include <malloc.h>
#define MaxSize 100
typedef int KeyType;
typedef char InfoType[10];
typedef struct
{
    KeyType key;
    InfoType data;
} RecType;
void Merge(RecType R[],int low,int mid,int high)
{
    RecType *R1;
    int i=low,j=mid+1,k=0;
    R1=(RecType *)malloc((high-low+1)*sizeof(RecType));
    while(i<=mid && j<=high)
    {
        if(R[i].key<=R[j].key)
            R1[k++]=R[i++];
        else
            R1[k++]=R[j++];
    }
    while(i<=mid)
        R1[k++]=R[i++];
    while(j<=high)
        R1[k++]=R[j++];
    for(k=0,i=low; i<=high; ++i,++k)
        R[i]=R1[k];
}
void MergePass(RecType R[],int length,int n)
{
    int i;
    for(i=0; i+2*length-1<n; i+=2*length)
        Merge(R,i,i+length-1,i+2*length-1);
    if(i+length-1<n)
        Merge(R,i,i+length-1,n-1);
}
void MergeSort(RecType R[],int n)
{
    int length;
    for(length=1; length<n; length*=2)
        MergePass(R,length,n);
}
int main()
{
    int i,n=10;
    RecType R[MaxSize];
    KeyType a[]= {6,8,7,9,0,1,3,2,4,5};
    for (i=0; i<n; i++)
        R[i].key=a[i];
    printf("排序前:");
    for (i=0; i<n; i++)
        printf("%d ",R[i].key);
    printf("\n");
    MergeSort(R,n);
    printf("排序后:");
    for (i=0; i<n; i++)
        printf("%d ",R[i].key);
    printf("\n");
    return 0;
}

运行结果：