# Demo entry 6746707

Sardinas–Patterson algorithm

Submitted by anonymous on May 30, 2018 at 18:09
Language: C++. Code size: 3.1 kB.

```#include <algorithm>
#include <iostream>
#include <fstream>
#include <string>
#include <cstring>
#include <vector>
#include <set>
using namespace std;

//码元数量
const int max_size = 2;
//最大码字长度
const int max_len = 100;
const int max_node = 1000;
//后缀数组记录表
set<string> table;
bool cmp(string a, string b){
return a.length()<b.length();
}
void dfs(int id, string s, int state);
struct Trie{
int ch[max_node][max_size];
int val[max_node];
int size;
int idx(char c){
return c-'0';
}
void init(){
size = 1;
memset(ch[0], 0, sizeof(ch[0]));
}
//插入建树过程
int insert(string s, int v){
int u = 0, n = s.length();
int flag = 1;
vector<int> vec;
for(int i=0;i<n;i++){
int c = idx(s[i]);
if(!ch[u][c]){
memset(ch[size],0,sizeof(ch[size]));
val[size] = 0;
ch[u][c] = size++;
}
if(val[u]==1&&v==-1){
vec.push_back(u);
}
u = ch[u][c];
}
for(int i=0;i<vec.size();i++){

dfs(vec[i],"",-1);
}
if(val[u]==1)
flag = -1;
val[u] = v;
return flag*u;
}
}Tree;

//判断是否有码字重合

bool same = false;

int len;

//从当前节点遍历树，找出所有后缀数组

void dfs(int id, string s, int state){
if(same)
return;

bool none = true;
for(int i=0;i<max_size;i++){
if(Tree.ch[id][i]){
none = false;
break;
}
}

//插入后缀数组字符
if(state==-1&&Tree.val[id]==-1){
if(table.find(s)==table.end()){
int x = Tree.insert(s,-1);
if(x<0){
same = true;
return;
}
table.insert(s);
dfs(x,"",1);
}
}

if(state==1&&Tree.val[id] == 1){

int x = -2;
if(s!=""&&table.find(s)==table.end()){
x = Tree.insert(s,-1);
table.insert(s);
if(x<0){
same = true;
cout<<endl<<"same  "<<s<<endl<<endl;
return;
}
dfs(x,"",1);
}
}
if(none)
return;
//向树的下一层搜索
for(int i=0;i<max_size;i++){
if(Tree.ch[id][i]){
char temp = '0'+i;
dfs(Tree.ch[id][i], s+temp,1);
}
}
}
//记录总码字
string list[max_len];
int pos[max_len];

{
ifstream fin("input.txt");
const int LINE_LENGTH = 100;
char str[LINE_LENGTH];
string s;
int i=0;
Tree.init();
cout<<"building tree"<<endl;
//文件读入
while( fin.getline(str,LINE_LENGTH) )
{
list[i] = str;
//pos[i] = Tree.insert(list[i],1);
i++;
//cout << "NO."<<i<<"  :"<<pos[i-1]<<" "<< list[i-1] << endl;
}
sort(list,list+i,cmp);

for(int j=0;j<i;j++){
pos[j] = Tree.insert(list[j],1);
cout << "NO."<<j<<"  :"<<pos[j-1]<<" "<< list[j-1] << endl;
}
return i;
}

int main()
{

int len;
for(int i=0;i<len&&!same;i++){
dfs(pos[i],"",1);
}
if(same)
cout<<"NO"<<endl;
else{
cout<<"YES"<<endl;
}
set<string>::iterator iter;
for(iter = table.begin();iter!=table.end();iter++){
cout<<*iter<<endl;
}

return 0;
}
```

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