把字符串倍长复制了。。。直接后缀数组求出rank就好了QAQ
1 /************************************************************** 2 Problem: 1031 3 User: rausen 4 Language: C++ 5 Result: Accepted 6 Time:1252 ms 7 Memory:4908 kb 8 ****************************************************************/ 9 10 #include <cstdio> 11 #include <cstring> 12 #include <algorithm> 13 14 using namespace std; 15 const int N = 2e5 + 5; 16 17 char s[N]; 18 int l, sa[N], rank[N]; 19 int x[N], y[N], sum[N]; 20 21 inline void Sort(int *a, int *b, int *c, int n, int m) { 22 static int i; 23 for (i = 0; i <= m; ++i) sum[i] = 0; 24 for (i = 0; i < n; ++i) ++sum[c[a[i]]]; 25 for (i = 1; i <= m; ++i) sum[i] += sum[i - 1]; 26 for (i = n - 1; ~i; --i) 27 b[--sum[c[a[i]]]] = a[i]; 28 } 29 30 void make_sa(char *s) { 31 int i, j; 32 for (i = 0; i < l; ++i) x[i] = s[i], rank[i] = i; 33 Sort(rank, sa, x, l, 256); 34 rank[sa[0]] = 1; 35 for (i = 1; i < l; ++i) 36 rank[sa[i]] = rank[sa[i - 1]] + (x[sa[i]] != x[sa[i - 1]]); 37 for (i = 1; i <= l; i <<= 1) { 38 for (j = 0; j < l; ++j) 39 x[j] = rank[j], y[j] = j + i < l ? rank[j + i] : 0, sa[j] = j; 40 Sort(sa, rank, y, l, l), Sort(rank, sa, x, l, l); 41 rank[sa[0]] = 1; 42 for (j = 1; j < l; ++j) 43 rank[sa[j]] = rank[sa[j - 1]] + (x[sa[j]] != x[sa[j - 1]] || y[sa[j]] != y[sa[j - 1]]); 44 if (rank[sa[l - 1]] == l) return; 45 } 46 } 47 48 int main() { 49 int i; 50 gets(s), l = strlen(s); 51 for (i = l; i < l << 1; ++i) s[i] = s[i - l]; 52 l <<= 1; 53 make_sa(s); 54 for (i = 0; i < l; ++i) 55 if (sa[i] < l / 2) putchar(s[sa[i] + l / 2 - 1]); 56 putchar(' '); 57 return 0; 58 }