[字尾陣列 模板]
阿新 • • 發佈:2018-11-09
我是用 HDU-2594來測試的本模板
程式碼
#include <bits/stdc++.h>
#include <iostream>
#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <string>
#include <math.h>
#include <stack>
#include <vector>
#include <queue>
#include <set>
#include <map>
using namespace std;
#define rep(i, l, r) for(int i = l; i < r; i++)
#define per(i, r, l) for(int i = r; i >= l; i--)
#define dbgln(...) cerr<<"["<<#__VA_ARGS__":"<<(__VA_ARGS__)<<"]"<<"\n"
#define dbg(...) cerr<<"["<<#__VA_ARGS__":"<<(__VA_ARGS__)<<"]"
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int>pii;
const int N = (int) 50000 * 3 + 10000; // 這裡不知道為啥 陣列必須開大好多才行,不然RE
const int M = (int) 1e6 + 11;
const int MOD = (int) 1e9 + 7;
const int INF = (int) 0x3f3f3f3f;
const ll INFF = (ll) 0x3f3f3f3f3f3f3f3f;
/*-----------------------------------------------------------*/
int n, k;
int Rank[N + 1], sa[N + 1], height[N + 1], tmp[N + 1];
int MIN[N + 1][40];
bool cmp_sa(int i, int j){
if(Rank[i] != Rank[j]) return Rank[i] < Rank[j];
else {
int ri = i + k <= n ? Rank[i + k] : -1;
int rj = j + k <= n ? Rank[j + k] : -1;
return ri < rj;
}
}
void SA(string s){ // 排名為 1 - n ,其他都是0 - (n - 1)
// sa , 0 - (n - 1)
n = s.size();
for(int i = 0; i <= n; i++){
sa[i] = i; Rank[i] = (i < n) ? s[i] : -1;
}
for(k = 1; k <= n; k <<= 1){
sort(sa, sa + n + 1, cmp_sa);
tmp[sa[0]] = 0;
for(int i = 1; i <= n; i++){
tmp[sa[i]] = tmp[sa[i - 1]] + (cmp_sa(sa[i - 1], sa[i]) ? 1 : 0);
}
for(int i = 0; i <= n; i++){
Rank[i] = tmp[i];
}
}
// height and rank
for(int i = 0; i <= n; i++) Rank[sa[i]] = i;
int h = 0;
height[0] = 0;
for(int i = 0; i < n; i++){
int j = sa[Rank[i] - 1];
if(h > 0) h--;
for(;j + h < n && i + h < n; h++){
if(s[j + h] != s[i + h]) break;
}
height[Rank[i] - 1] = h;
} // height[i] = sa[i]於sa[i + 1] 的lcp
// RMQ
for(int i = 1; i <= n; i++) MIN[i][0] = height[i];
for(int j = 1; (1 << j) <= n; j++){
for(int i = 1; i <= n; i++){
MIN[i][j] = min(MIN[i][j - 1], MIN[i + (1 << (j - 1))][j - 1]);
}
}
}
int LCP(int L, int R){ // 0 - (n - 1)
L = Rank[L]; R = Rank[R];
if(L > R) swap(L, R);
R--;
int k = 0;
while((1 << (k + 1)) <= R - L + 1) k++; // 2^k可以完全覆蓋
return min(MIN[L][k], MIN[R - (1 << k) + 1][k]);
}
int main(){
string a, b, s;
while(cin >> a >> b){
s = ""; s += a; s += '$'; s += b;
SA(s);
//dbgln(s);
/*
for(int i = 0; i <= (int)s.size(); i++){
dbg(i); dbg(sa[i]); dbgln(Rank[i]);
}
*/
bool flag = 0;
for(int i = a.size() + 1; s[i]; i++){
if(LCP(0, i) == ((int)s.size() - i)){
for(int j = i; s[j]; j++){
printf("%c", s[j]);
}
printf(" %d\n", (int)s.size() - i);
flag = 1;
break;
}
}
if(!flag) puts("0");
}
return 0;
}