【BZOJ 1031】【JSOI 2007】字符加密Cipher
后缀数组模板题,看了一天的后缀数组啊,我怎么这么弱TwT
#include<cstdio> #include<cstring> #include<algorithm> using namespace std; const int N = 200003; char s[N]; int t1[N], t2[N], sa[N], c[N]; void st(int *x, int *y, int n, int m) { int i; for(i = 0; i < m; ++i) c[i] = 0; for(i = 0; i < n; ++i) ++c[x[y[i]]]; for(i = 1; i < m; ++i) c[i] += c[i - 1]; for(i = n - 1; i >= 0; --i) sa[--c[x[y[i]]]] = y[i]; } void mkhz(char *a, int n, int m) { int i, j, p, *x = t1, *y = t2, *t; for(i = 0; i < n; ++i) x[i] = s[i], y[i] = i; st(x, y, n, m); for(j = 1, p = 1; p < n; j <<= 1, m = p) { for(p = 0, i = n - j; i < n; ++i) y[p++] = i; for(i = 0; i < n; ++i) if (sa[i] >= j) y[p++] = sa[i] - j; st(x, y, n, m); for(t = x, x = y, y = t, p = 1, x[sa[0]] = 0, i = 1; i < n; ++i) x[sa[i]] = y[sa[i]] == y[sa[i - 1]] && y[sa[i] + j] == y[sa[i - 1] + j] ? p - 1 : p++; } } int main() { scanf("%s", s + 1); int len = strlen(s + 1); for(int i = 1; i <= len; ++i) s[len + i] = s[i]; s[0] = 0; mkhz(s, len * 2 + 1, 256); for(int i = 1, cnt = 1; cnt <= len; ++i) if (sa[i] <= len) printf("%c", s[sa[i] + len - 1]), ++cnt; puts(""); return 0; }
后缀数组好厉害~~~
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