suffix array board

 1 #include<bits/stdc++.h>
 2 #define LL long long
 3 #define fi first
 4 #define se second
 5 #define mk make_pair
 6 #define pii pair<int,int>
 7 
 8 using namespace std;
 9 
10 const int N=2e5+7;
11 const int M=1e4+7;
12 const int inf=0x3f3f3f3f;
13 const LL INF=0x3f3f3f3f3f3f3f3f;
14 const int mod=1e9 + 7;
15 
16 char s[N];
17 int sa[N], t[N], t2[N], c[N], rk[N], height[N], n;
18 
19 void buildSa(int m) {
20     int i, j = 0, k = 0, *x = t, *y = t2;
21     for(i = 0; i < m; i++) c[i] = 0;
22     for(i = 0; i < n; i++) c[x[i] = s[i]]++;
23     for(i = 1; i < m; i++) c[i] += c[i - 1];
24     for(i = n - 1; i >= 0; i--) sa[--c[x[i]]] = i;
25     for(int k = 1; k <= n; k <<= 1) {
26         int p = 0;
27         for(i = n - k; i < n; i++) y[p++] = i;
28         for(i = 0; i < n; i++) if(sa[i] >= k) y[p++] = sa[i] - k;
29         for(i = 0; i < m; i++) c[i] = 0;
30         for(i = 0; i < n; i++) c[x[y[i]]]++;
31         for(i = 1; i < m; i++) c[i] += c[i - 1];
32         for(i = n - 1; i >= 0; i--) sa[--c[x[y[i]]]] = y[i];
33         swap(x, y);
34         p = 1; x[sa[0]] = 0;
35         for(int i = 1; i < n; i++) {
36             if(y[sa[i - 1]] == y[sa[i]] && y[sa[i - 1] + k] == y[sa[i] + k])
37                 x[sa[i]] = p - 1;
38             else x[sa[i]] = p++;
39         }
40         if(p >= n) break;
41         m = p;
42      }
43 
44      for(i = 0; i < n; i++) rk[sa[i]] = i;
45      for(i = 0; i < n; i++) {
46         if(k) k--;
47         j = sa[rk[i] - 1];
48         while(s[i + k] == s[j + k]) k++;
49         height[rk[i]] = k;
50      }
51 }
52 int main() {
53     scanf("%d", &n);
54     scanf("%s", s);
55     buildSa(130);
56     return 0;
57 }