算法导论8-3变长数据项排序-整数数组-字符串

//算法导论8-3，变长数据项的排序
#include <iostream>
#include <ctime>
#include <boost/timer/timer.hpp>
using namespace std;
using namespace boost::timer;

int bits(int i)//找出每位数的位数,正数为正，负数为负
{
int radix=1;
while (i/10)
{
radix++;
i/=10;
}
return (i>=0)?radix:(-radix);
}

void find_max_min(int *aCount,int &max,int &min,int n)
{//查找数字的最大位数
max=aCount[0];//初始化
min=max;
int tmp;
for(int i=1;i<n;++i){
tmp=aCount[i];
if(max<tmp){
max=tmp;
}else if(min>tmp){
min=tmp;
}
}
}
void radix_sort(int *bucket,int n)//基数排序
{
int *s=new int
;
int bit=abs(bits(bucket[0]));//此处用正数
int radix=1;
int *b=new int
;
for(int i=0;i<bit;++i,radix*=10){
for(int j=0;j<n;++j){
s[j]=(bucket[j]/radix)%10;//存储每轮的值
}
int max,min;
find_max_min(s,max,min,n);
int count=max-min+1;
int *c=new int[count];
memset(c,0,count*sizeof(int));
for(int j=0;j<n;++j){
c[s[j]-min]++;
}
for(int j=1;j<count;++j){
c[j]+=c[j-1];
}

for(int j=n-1;j>=0;--j){
b[c[s[j]-min]-1]=bucket[j];
c[s[j]-min]--;
}
/*for(int j=0;j<n;++j){
bucket[j]=b[j];
}*/
memcpy(bucket,b,n*sizeof(int));
delete[]c;
}
delete[]b;
delete[]s;
}

void bucket_sort(int *a,int n)//桶排序
{
int *aCount=new int
;//记录a[i]的位数
for(int i=0;i<n;++i){
int bit=bits(a[i]);//位数
aCount[i]=bit;
}

int max,min;
find_max_min(aCount,max,min,n);
int count=max-min+1;
int *b=new int[count];//用来存放不同位数的数字的个数
memset(b,0,count*sizeof(int));//初始化为零

for(int i=0;i<n;++i){//统计每个桶的元素个数
b[aCount[i]-min]++;
}

int **bucket=new int *[count];
int *flag=new int [count];
for(int i=0;i<count;++i){
bucket[i]=new int[b[i]];//第i个桶有b[i]个元素
flag[i]=0;//初始化
}

for(int i=0;i<n;++i){//将相关元素放到相应的桶中
bucket[aCount[i]-min][flag[aCount[i]-min]++]=a[i];
}

int k=0;
for(int i=0;i<count;++i){
radix_sort(bucket[i],b[i]);
for(int j=0;j<b[i];++j){
a[k++]=bucket[i][j];
}
}
}

int main()
{
srand(time(NULL));
int count;
while (count=rand()%16,count<4);
count=100;
int *a=new int[count];
for(int i=0;i<count;++i){
a[i]=rand()%201-100;
cout<<a[i]<<"\t";
}
//a[0]=-2,a[1]=-5,a[2]=-3,a[3]=1,a[4]=-2;
cout<<endl;
cpu_timer t1;
t1.start();
bucket_sort(a,count);
t1.stop();

for(int i=0;i<count;++i){
cout<<a[i]<<"\t";
}
cout<<endl;
delete[]a;
cout<<t1.format();
}

#include <iostream>
#include <ctime>
#include <boost/timer/timer.hpp>
using namespace std;
using namespace boost::timer;
void find_max_min(char **str,int &max,int &min,int index,int offset,int n)
{
max=str[offset][index],min=str[offset][index];
for(int i=1;i<n;++i){
if(max<str[i+offset][index]){
max=str[i+offset][index];
}else if(min>str[i+offset][index]){
min=str[i+offset][index];
}
}
}

int insertion_sort_stable(char **str,int index,int offset,int n){//插入排序版本，对元素按照长短进行排序
int key,j;
int num=(strlen(str[offset])==index)?1:0;
for(int i=1;i<n;++i){
if((key=strlen(str[i+offset]))==index){
num++;
}
char *keystr=str[i+offset];
j=i-1;
while (j>=0 && strlen(str[j+offset])>key){
str[j+1+offset]=str[j+offset];
--j;
}
str[j+1+offset]=keystr;
}
return num;
}

int fast_sort_unstable(char **str,int index,int offset,int n)//快速排序版本,将字符串等于index的放在前面
{
int p=-1;
char *keystr;
for(int i=0;i<n;++i){
if(strlen(str[offset+i])==index){
p++;
keystr=str[i+offset];
str[i+offset]=str[offset+p];
str[offset+p]=keystr;
}
}
return p+1;
}

void counting_sort(char **str,int index,int offset,int n)//计数排序
{
char **strCpy=new char *
;//临时存储字符串
int max,min;
find_max_min(str,max,min,index,offset,n);
int count=max-min+1;
int *c=new int[count];
memset(c,0,count*sizeof(int));
for(int i=0;i<n;++i){
c[str[i+offset][index]-min]++;
}
int tmp=c[count-1];//存储最后一组的元素个数值

for(int i=1;i<count;++i){
c[i]=c[i]+c[i-1];
}
for(int i=n-1;i>=0;--i){
//strCpy[c[str[i+offset][index]-min]-1]=new char[strlen(str[i+offset])+1];//初始化内存空间
//memcpy(strCpy[c[str[i+offset][index]-min]-1],str[i+offset],strlen(str[i+offset])+1);
strCpy[c[str[i+offset][index]-min]-1]=str[i+offset];
c[str[i+offset][index]-min]--;//每组字符个数减1
}
for(int i=0;i<n;++i){
//memcpy(str[i+offset],strCpy[i],strlen(strCpy[i])+1);
str[i+offset]=strCpy[i];
}

for(int i=0;i<count-1;++i){
c[i]=c[i+1]-c[i];//恢复原始每组元素值
}
c[count-1]=tmp;

int dd;//存储每组相同元素的个数
for(int i=0;i<count;++i){
if(i!=0){
c[i]=c[i]+c[i-1];
}
dd=(i>0)?(c[i]-c[i-1]):c[0];
if(dd>1){
int k=(i>0)?c[i-1]:0;
//int num = insertion_sort_stable(str,index+1,offset+k,dd);//返回可忽略的数字
int num=fast_sort_unstable(str,index+1,offset+k,dd);//返回可忽略的数字
/*for(int j=0;j<dd;++j){
cout<<str[offset+k+j]<<"\t";
}
cout<<endl;*/
counting_sort(str,index+1,offset+k+num,dd-num);//递归调用
}
}
delete [] strCpy;
delete[]c;
}

int main()
{
srand(time(NULL));
int count;
while (count=rand()%100,count<50);
count=40000000;
char **str=new char*[count];
int size;
for(int i=0;i<count;++i){
while (size=rand()%10,size<2);
str[i]=new char[size];
int j=0;
while (j<size-1){//随机生成字符串
str[i][j]=rand()%26+'A'+(rand()%2)*32;//随机生成字母
++j;
}
str[i][j]='\0';
}
/*str[0]=new char [2];
str[1]=new char [3];
str[2]=new char [4];
strcpy(str[2],"a");
strcpy(str[0],"a");
strcpy(str[1],"ab");

for(int i=0;i<count;++i){
cout<<str[i]<<"\t";
}
cout<<endl;*/
cout<<endl<<"*******************************"<<endl;
cout<<count<<" strings"<<endl;
cpu_timer t1;
t1.start();
counting_sort(str,0,0,count);
t1.stop();
cout<<endl<<"*******************************"<<endl;
//for(int i=0;i<count;++i){
//	cout<<str[i]<<"\t";
//}
//cout<<endl;
cout<<t1.format();
for(int i=0;i<count;++i){
delete [] str[i];
//str[i]=NULL;
}
delete[] str;
}

#include <iostream>
#include <algorithm>
#include <boost/timer/timer.hpp>
#include <ctime>
using namespace std;
using namespace boost::timer;

int compar_words(const void *p, const void *q)
{
return strcmp(*(char **)p, *(char **)q);
}
int main()
{
srand(time(NULL));
int count;
while (count=rand()%100,count<50);
count=40000000;
char **str=new char*[count];
int size=5;
for(int i=0;i<count;++i){
while (size=rand()%20,size<2);
size=5;
str[i]=new char[size];
int j=0;
while (j<size-1){//随机生成字符串
str[i][j]=rand()%26+'A'+(rand()%2)*32;//随机生成字母
++j;
}
str[i][j]='\0';
}
cout<<"*******************************"<<endl;
cout<<count<<" strings"<<endl;
cpu_timer t1;
t1.start();
qsort(str,count,sizeof(str[0]),compar_words);
cout<<"*******************************"<<endl;
t1.stop();
cout<<t1.format();
for(int i=0;i<count;++i){
delete[] str[i];
}
delete[] str;
}