算法导论-C++实现-UDC uniquely decodable唯一可编码问题算法

#include <iostream>
#include <string.h>
#include <malloc.h>
#define CNUM 2
#define CWNUM 5
#define MAXCWLENGTH 10
using namespace std;
char* character;
char** codeword;
struct SContainer *ss;
struct SContainer *ssTail;
struct SContainer{
char* s;
struct SContainer *next;
};
bool isInSContainer(char* str,struct SContainer *t){
struct SContainer *temp;
temp=t;
while(temp!=NULL){
// cout<<str<<" and "<<temp->s<<" compare"<<endl;
if(!strcmp(temp->s,str)){
return true;
}
// cout<<str<<" and "<<temp->s<<" not equal"<<endl;
temp=temp->next;
}
return false;
}
void initialize(){
character=new char[CNUM];
character[0]='0';
character[1]='1';
codeword=new char*[CWNUM];
codeword[0]="01";
codeword[1]="001";
// codeword[2]="01";
codeword[2]="10";
codeword[3]="010";
codeword[4]="100";
// codeword[4]="1000";
ss=NULL;
ssTail=NULL;
/*
if((ss=(SContainer *)malloc(sizeof(SContainer)))==NULL){
cout<<"not enough space."<<endl;
exit(1);
}
*/
// cout<<character[1]<<endl;
// cout<<codeword[2]<<endl;
}
bool firstStep(){
for(int i=0;i<CWNUM-1;i++){
for(int j=i+1;j<CWNUM;j++){
if(!strcmp(codeword[i],codeword[j])){
return false;
}
}
}
return true;
}
char* getSuffixOf(char* Ci,char *Cj){
int index=0;
char* suffix=new char[MAXCWLENGTH+1];
while(Ci[index]!='/0' && Cj[index]!='/0'){
if(Ci[index]!=Cj[index])
return NULL;
index++;
}
// cout<<"Finish testing"<<endl<<"Begin to get suffix"<<endl;
// cout<<"index="<<index<<endl;
int i=0;
while(Ci[index]!='/0'){
suffix[i]=Ci[index];
index++;
i++;
}
while(Cj[index]!='/0'){
suffix[i]=Cj[index];
index++;
i++;
}
suffix[i]='/0';
// cout<<"Get suffix :"<<suffix<<endl;
return suffix;
}
void addInSContainer(char *t){
struct SContainer *temp;
if((temp=(SContainer *)malloc(sizeof(SContainer)))==NULL){
cout<<"not enough space."<<endl;
exit(1);
}
temp->s=t;
temp->next=ss;
ss=temp;
}
void addInSContainerTail(char *t){
struct SContainer *temp;
if((temp=(SContainer *)malloc(sizeof(SContainer)))==NULL){
cout<<"not enough space."<<endl;
exit(1);
}
temp->s=t;
temp->next=NULL;
if(ss==NULL){
ssTail=temp;
ss=temp;
}
else{
ssTail->next=temp;
ssTail=temp;
}
}
void secondStep(){
for(int i=0;i<CWNUM-1;i++){
for(int j=i+1;j<CWNUM;j++){
char* temp;
temp=getSuffixOf(codeword[i],codeword[j]);
if(temp!=NULL && !isInSContainer(temp,ss)){
addInSContainerTail(temp);
}
}
}
}
bool finalStep(){
struct SContainer *ttt;
ttt=ss;
char *temp;
while(ttt!=NULL){
temp=ttt->s;
for(int i=0;i<CWNUM;i++){
if(!strcmp(codeword[i],temp)){
return false;
}
char* suf;
suf=getSuffixOf(temp,codeword[i]);
if(suf!=NULL && !isInSContainer(suf,ss)){
addInSContainerTail(suf);
}
}
ttt=ttt->next;
}
return true;
}
int main(){
initialize();
/*
ss->s="01";
struct SContainer *s1;
if((s1=(SContainer *)malloc(sizeof(SContainer)))==NULL){
cout<<"not enough space."<<endl;
exit(1);
}
ss->next=s1;
s1->s="10";
s1->next=NULL;
if(isInSContainer("10",ss)){
cout<<"exist"<<endl;
}
else{
cout<<"not exist"<<endl;
}
*/

if(firstStep()){
cout<<"No error occurs during first step"<<endl<<"There goes the second step"<<endl;;
secondStep();
cout<<"Second step finished"<<endl<<"There goes the final step"<<endl;
if(finalStep())
cout<<"Final step finished"<<endl<<"It is uniquely decodable"<<endl;
else
cout<<"Final step finished"<<endl<<"It is not uniquely decodable"<<endl;
}
else
cout<<"Not uniquely decodable"<<endl;

// if(getSuffixOf("0101001","011")==NULL)
// cout<<"No suffix"<<endl;
// addInSContainerTail("00");
// addInSContainerTail("01");
// addInSContainerTail("10");
// addInSContainerTail("11");
// if(isInSContainer("111",ss)){
// cout<<"exist"<<endl;
// }
// else{
// cout<<"not exist"<<endl;
// }
// struct SContainer *ttt;
// ttt=ss;
// while(ttt!=NULL){
// cout<<ttt->s<<endl;
// ttt=ttt->next;
// }
// cout<<"Tail:"<<ssTail->s<<endl;
return 0;
}