二分法排序

#include<stdio.h>

#define MAXNUM 100
typedef int KeyType;
typedef int DataType;

typedef struct {
    KeyType key;       /* 排序码字段 */
    /*DataType info;   记录的其它字段 */
} RecordNode;

typedef struct {
    int n;               /* n为文件中的记录个数,n<MAXNUM */
    RecordNode record[MAXNUM];
} SortObject;

void binSort(SortObject * pvector) {      /* 按递增序进行二分法插入排序 */
    int i, j, left, mid, right;
    RecordNode temp;
    RecordNode *data = pvector->record;
    for( i = 1; i < pvector->n; i++ ) {
        temp = data[i];
        left = 0;  right = i-1;           /* 置已排序区间的下、上界初值 */
        while (left <= right) {
            mid = (left + right)/2;       /* mid指向已排序区间的中间位置 */
            if (temp.key < data[mid].key)
                right = mid-1;            /* 插入元素应在左子区间 */
            else left = mid+1;            /* 插入元素应在右子区间 */
        }
        for (j = i-1;  j >= left;  j--)
            data[j+1] = data[j];          /* 将排序码大于ki的记录后移 */
        if (left != i) data[left] = temp;
    }
}

SortObject vector={10, 49,38,65,97,76,13,27,49,50,101};

int main(){
    int i;
    binSort(&vector);
    for(i = 0; i < vector.n; i++)
        printf("%d ", vector.record[i]);
    getchar();
    return 0;
}

修改代码如下:

/* 二分法插入排序的算法源程序*/

#include<stdio.h>
#include<iostream.h>
#include<iomanip.h>
#include<stdlib.h>
#include<time.h>
#include<malloc.h>

#define MAXNUM 100

#define MAXI 10;
typedef int KeyType;
typedef int DataType;

typedef struct {
    KeyType key;       /* 排序码字段 */
    /*DataType info;   记录的其它字段 */
} RecordNode;

typedef struct {
    int n;               /* n为文件中的记录个数,n<MAXNUM */
    RecordNode record[MAXNUM];
} SortObject;

void binSort(SortObject * pvector) {      /* 按递增序进行二分法插入排序 */
    int i, j, left, mid, right;
    RecordNode temp;
    RecordNode *data = pvector->record;
    for( i = 1; i < pvector->n; i++ ) {
        temp = data[i];
        left = 0;  right = i-1;           /* 置已排序区间的下、上界初值 */
        while (left <= right) {
            mid = (left + right)/2;       /* mid指向已排序区间的中间位置 */
            if (temp.key < data[mid].key)
                right = mid-1;            /* 插入元素应在左子区间 */
            else left = mid+1;            /* 插入元素应在右子区间 */
        }
        for (j = i-1;  j >= left;  j--)
            data[j+1] = data[j];          /* 将排序码大于ki的记录后移 */
        if (left != i) data[left] = temp;
    }
}

//SortObject vector={10, 49,38,65,97,76,13,27,49,50,101};

int main(){
    int i;
    SortObject vector;

vector.n=MAXI;
    //vector.record= new record[MAXNUM]; //再次在这个地方碰到问题,vector.record= new vector.record= RecordNode[MAXNUM]; 事实上,在这//里,问题更加容易处理,就是直接定义vector,然后,对n初始化即可
    for( i=1;i<vector.n;i++)
    srand(time(0));
   {//a.record[i] = (pu)malloc( sizeof(RecordNode));
    vector.record[i].key=rand()%80;
    //a.record[i].data=rand()%100;
   }
    binSort(&vector);
    for(i = 0; i < vector.n; i++)
        printf("%d ", vector.record[i]);
    getchar();
    return 0;
}

经过测试运行后的完整代码:

/* 二分法插入排序的算法源程序*/

#include<stdio.h>
#include<iostream.h>
#include<iomanip.h>
#include<stdlib.h>
#include<time.h>
#include<malloc.h>

#define MAXNUM 100
#define MAXI 10;
typedef int KeyType;
typedef int DataType;

typedef struct {
    KeyType key;       /* 排序码字段 */
    /*DataType info;   记录的其它字段 */
} RecordNode;

typedef struct {
    int n;               /* n为文件中的记录个数,n<MAXNUM */
    RecordNode record[MAXNUM];//相当于typedef   RecordNode record[MAXNUM];
} SortObject;

void binSort(SortObject * pvector ,int n) {      /* 按递增序进行二分法插入排序 */
    int i, j, left, mid, right;
    RecordNode temp;
    RecordNode *data = pvector->record;
    for( i = 1; i < pvector->n; i++ ) {
        temp = data[i];
        left = 0;  right = i-1;           /* 置已排序区间的下、上界初值 */
        while (left <= right) {
            mid = (left + right)/2;       /* mid指向已排序区间的中间位置 */
            if (temp.key < data[mid].key)
                right = mid-1;            /* 插入元素应在左子区间 */
            else left = mid+1;            /* 插入元素应在右子区间 */
        }
        for (j = i-1;  j >= left;  j--)
            data[j+1] = data[j];          /* 将排序码大于ki的记录后移 */
        if (left != i) data[left] = temp;
       for(int k=0;k<n;k++)
         cout<<setw(4)<<pvector->record[k].key;
         cout<<endl;
    }
}

//SortObject vector={10, 49,38,65,97,76,13,27,49,50,101};

int main(){
    int i;
    SortObject vector;
    vector.n=MAXI;
    //vector.record = new RecordNode ;
    srand(time(0));
    for( i=0;i<vector.n;i++)
    {
       //a.record[i] = (pu)malloc( sizeof(RecordNode));
     vector.record[i].key=rand()%80;
    //a.record[i].data=rand()%100;
    }
    cout<<"排序前数组:\n";
    binSort(&vector,vector.n);
    cout<<"\nbinsort执行完毕 ,排序后数组:\n";
    for(i = 0; i < vector.n; i++)
        cout<<setw(4)<<vector.record[i].key;
         cout<<endl;
    cout<<"\n程式执行完毕\n"<<endl;
    //getchar();
    return 0;
}

image

 

binSort(SortObject * pvector ,int n)算法的深入分析如下:

关于mid = (left + right)/2; 对于除不整的情况,进行模拟,

代码如下:

#include "stdio.h"
#define MAXI 10
void main()
{
    int right;
    int left;
    int mid;
    int i;
    for( i=0;i<MAXI;i++)
    {scanf("%3d,%3d",&right,&left);//注意用逗号隔开,在输入时
    mid=(right+left)/2;
    printf("%3d\n",mid);
    }
}

证实情况是 取整数,这个无所谓,反正,就是划分区域,具体是那个那个不重要,重要的是,所以要分析的对象均没有遗漏,显然这点满足

image

posted @ 2009-05-12 15:51  fleetwgx  阅读(828)  评论(0编辑  收藏  举报