P3809 【模板】后缀排序
1 #include <bits/stdc++.h> 2 using namespace std; 3 const int maxn = 1e6+5; 4 char s[maxn]; 5 int sa[maxn], t[maxn], t2[maxn], c[maxn]; 6 int n; 7 //构造字符串s的后缀数组， 每个字符值必须为0 ～ m-1 8 void build_sa(int m) { 9 int *x = t, *y = t2; 10 //基数排序 11 for(int i = 0; i < m; i++) c[i] = 0; 12 for(int i = 0; i < n; i++) c[x[i] = s[i]]++; 13 for(int i = 1; i < m; i++) c[i] += c[i-1]; 14 for(int i = n-1; i >= 0; i--) sa[--c[x[i]]] = i; 15 for(int k = 1; k <= n; k <<= 1) { 16 int p = 0; 17 //直接利用sa数组排序第二关键字 18 for(int i = n-k; i < n; i++) y[p++] = i; 19 for(int i = 0; i < n; i++) if(sa[i] >= k) y[p++] = sa[i] - k; 20 //基数排序第一关键字 21 for(int i = 0; i < m; i++) c[i] = 0; 22 for(int i = 0; i < n; i++) c[x[y[i]]]++; 23 for(int i = 1; i < m; i++) c[i] += c[i-1]; 24 for(int i = n-1; i>= 0; i--) sa[--c[x[y[i]]]] = y[i]; 25 //根据sa和y数组计算新的x数组 26 swap(x, y); 27 p = 1; 28 x[sa[0]] = 0; 29 for(int i = 1; i < n; i++) 30 x[sa[i]] = (y[sa[i-1]] == y[sa[i]] && y[sa[i-1]+k] == y[sa[i]+k] ? p-1 : p++); 31 if(p >= n) break; 32 m = p; 33 } 34 } 35 int main() { 36 scanf("%s",s); n = strlen(s); 37 build_sa(123); 38 printf("%d",sa[0]+1); 39 for (int i = 1; i < n; i++) 40 printf(" %d",sa[i]+1); 41 printf("\n"); 42 return 0; 43 }
