# Demo entry 6746705

Sardinas–Patterson algorithm

Submitted by anonymous on May 30, 2018 at 17:56
Language: C++. Code size: 2.8 kB.

```#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;
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];

int ReadDataFromFileLBLIntoCharArray()
{
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;
}
return i;
}

int main()
{

int len;
len = ReadDataFromFileLBLIntoCharArray();
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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