后缀数组的模板,这样说明就很详细了吧!


 

/*
 *	后缀数组模板-倍增法
 *	使用方法:
 *		1、读取字符串转换成int数组,长度为len,下标从0开始
 *		2、在字符串末尾加一字典序最小字符,一般为0,并找到最大的字符设为maxa
 *		3、调用函数da(num,sa,len+1,maxa+1)
 *				求得的sa数组的含义: sa[i]为第i字典序后缀字符串的首字母下标
 *		4、调用函数build_height(num,sa,len)
 *				求得的ranking数组的含义: ranking[i]为首字母下标为i的后缀数组的字典序的名次
 *				求得的height数组含义: height[i]为第i字典序后缀与第i-1字典序后缀的最长公共前缀,height[1] = 0;
 *				h[i]=height[rank[i]],也就是suffix(i)和在它前一名的后缀的最长公共前缀。
 *	注意事项:
 *		转化为数字的字符串最小数值必须不小于1,如果是0的话会Runtime Error,请自重.......
 */
#include <iostream>
#include <algorithm>
#include <cstdio>
#define INF 2*0x3f3f3f3f

using namespace std;
const int maxn = 200001; //注意数组的大小,记得更改

int wa[maxn], wb[maxn], wv[maxn], wss[maxn];
int cmp(int *r, int a, int b, int l) {
	return r[a] == r[b] && r[a + l] == r[b + l];
}
void da(int *r, int *sa, int n, int m) { //r为所求取的转化字符串 sa为求得的sa数组  n为数组长度+1  m为数组的最大值+1
	int i, j, p, *x = wa, *y = wb, *t;
	for (i = 0; i < m; i++) wss[i] = 0;
	for (i = 0; i < n; i++) wss[x[i] = r[i]]++;
	for (i = 1; i < m; i++) wss[i] += wss[i - 1];
	for (i = n - 1; i >= 0; i--) sa[--wss[x[i]]] = i;
	for (j = 1, p = 1; p < n; j *= 2, 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;
		for (i = 0; i < n; i++) wv[i] = x[y[i]];
		for (i = 0; i < m; i++) wss[i] = 0;
		for (i = 0; i < n; i++) wss[wv[i]]++;
		for (i = 1; i < m; i++) wss[i] += wss[i - 1];
		for (i = n - 1; i >= 0; i--) sa[--wss[wv[i]]] = y[i];
		for (t = x, x = y, y = t, p = 1, x[sa[0]] = 0, i = 1; i < n; i++)
			x[sa[i]] = cmp(y, sa[i - 1], sa[i], j) ? p - 1 : p++;
	}
	return;
}

int ranking[maxn], height[maxn];
void build_height(int *r, int *sa, int n) { //r为求得的转化原始数组,sa为已经求得的数组,n为len
	int i, j, k = 0;
	for (i = 1; i <= n; i++) ranking[sa[i]] = i;
	for (i = 0; i < n; height[ranking[i++]] = k) {
		for (k ? k-- : 0, j = sa[ranking[i] - 1]; r[i + k] == r[j + k]; k++);
	}
}

int sa[maxn], r[maxn];

int main() {
	freopen("in.in", "r", stdin);
	freopen("out.out", "w", stdout);
	return 0;
}