[学习笔记] 后缀数组

参考：https://www.cnblogs.com/zwfymqz/p/8413523.html

代码：

/*
* @Author: chenkexing
* @Date:   2020-01-19 19:14:09
* @Last Modified by:   chenkexing
* @Last Modified time: 2020-01-31 22:12:27
*/
// #pragma GCC optimize(2)
// #pragma GCC optimize(3)
// #pragma GCC optimize(4)
#include <algorithm>
#include  <iterator>
#include  <iostream>
#include   <cstring>
#include   <cstdlib>
#include   <iomanip>
#include    <bitset>
#include    <cctype>
#include    <cstdio>
#include    <string>
#include    <vector>
#include     <stack>
#include     <cmath>
#include     <queue>
#include      <list>
#include       <map>
#include       <set>
#include   <cassert>
// #include<bits/extc++.h>
// using namespace __gnu_pbds;
using namespace std;
#define pb push_back
#define fi first
#define se second
#define debug(x) cerr<<#x << " := " << x << endl;
#define bug cerr<<"-----------------------"<<endl;
#define FOR(a, b, c) for(int a = b; a <= c; ++ a)
 
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
 
const int inf = 0x3f3f3f3f;
const ll inff = 0x3f3f3f3f3f3f3f3f;
const int mod = 1e9+7;  
template<typename T>
inline T read(T&x){
    x=0;int f=0;char ch=getchar();
    while (ch<'0'||ch>'9') f|=(ch=='-'),ch=getchar();
    while (ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar();
    return x=f?-x:x;
}
 
/**********showtime************/

            const int maxn = 1e6+9;
            char str[maxn];

            int sa[maxn], rk[maxn], tp[maxn * 2];
            int box[maxn];
            int n;

            

            // 桶排序
            void tsort(int m) {
                for(int i=0; i<=m; i++) box[i] = 0;
                for(int i=1; i<=n; i++) box[rk[i]] ++;
                for(int i=1; i<=m; i++) 
                     box[i] += box[i-1];
                for(int i=n; i>=1; i--) {
                    sa[  box[rk[tp[i]]]-- ] = tp[i];
                }
            }

            int height[maxn];
            // height[i] 表示(排名为i的后缀)和(排名为i-1的后缀)的lcp
            void getH() {
                int j , k = 0;
                for(int i=1; i<=n; i++) {
                    if(k) k--;
                    j = sa[rk[i] - 1];
                    while(str[i + k] == str[j+k]) k++;
                    height[rk[i]] = k;
                }
            }
            
int main(){
            scanf("%s", str + 1);
            n = strlen(str+1);

            for(int i=1; i<=n; i++) {
                rk[i] = str[i] - '0';
                tp[i] = i;
            }

            tsort(200);

            for(int w=1, p = 0, m = 200; p < n; w = w * 2, m = p) {

                    p = 0;
                    for(int i = 1; i <= w; i++) tp[++p] = n - i + 1;
                    for(int i=1; i <= n; i++) {
                        if(sa[i] > w) tp[++p] = sa[i] - w;
                    }
                    // debug(p);
                    tsort(m);


                    for(int i=1; i<=n; i++) tp[i] = rk[i];
                    

                    rk[sa[1]] = p = 1;
                    for(int i=2; i<=n; i++) {
                        if(tp[sa[i]] == tp[sa[i-1]] && tp[sa[i] + w] == tp[sa[i-1] + w]) 
                            rk[sa[i]] = p;
                        else rk[sa[i]] = ++p;
                    }
                    
            }
            for(int i=1; i<=n; i++) printf("%d ", sa[i]);
            puts("");
            return 0;
}