字符串处理之后缀数组

#include<iostream>
#include<stdio.h>
#include<string.h>
using namespace std;
#define min(x,y) x>y? y:x
#define N 200010
int dp[N][33];
int wa[N], wb[N], wsf[N], wv[N], sa[N];
int ra[N], height[N], s[N];
char str[N], str1[N];
int cmp(int *r, int a, int b, int k)
{
    return r[a] == r[b] && r[a + k] == r[b + k];
}
void getsa(int *r, int *sa, int n, int m)
{
    int i, j, p, *x = wa, *y = wb, *t;
    for (i = 0; i < m; i++)  wsf[i] = 0;
    for (i = 0; i < n; i++)  wsf[x[i] = r[i]]++;
    for (i = 1; i < m; i++)  wsf[i] += wsf[i - 1];
    for (i = n - 1; i >= 0; i--)  sa[--wsf[x[i]]] = i;
    p = 1;
    j = 1;
    for (; 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++)  wsf[i] = 0;
        for (i = 0; i < n; i++)  wsf[wv[i]]++;
        for (i = 1; i < m; i++)  wsf[i] += wsf[i - 1];
        for (i = n - 1; i >= 0; i--)  sa[--wsf[wv[i]]] = y[i];
        t = x;
        x = y;
        y = t;
        x[sa[0]] = 0;
        for (p = 1, i = 1; i < n; i++)
            x[sa[i]] = cmp(y, sa[i - 1], sa[i], j) ? p - 1 : p++;
    }
}
void getheight(int *r, int n)
{
    int i, j, k = 0;
    for (i = 1; i <= n; i++)  ra[sa[i]] = i;
    for (i = 0; i < n; i++)
    {
        if (k)
            k--;
        else
            k = 0;
        j = sa[ra[i] - 1];
        while (r[i + k] == r[j + k])
            k++;
        height[ra[i]] = k;
    }
}
int main()
{
    while (cin >> str)
    {
        cin >> str1;
        int n = 0, len = strlen(str);
        for (int i = 0; i < len; i++)
            s[n++] = str[i] - 'a' + 1;
        s[n++] = 28;
        len = strlen(str1);
        for (int i = 0; i < len; i++)
            s[n++] = str1[i] - 'a' + 1;
        s[n] = 0;
        getsa(s, sa, n + 1, 30);
        getheight(s, n);
        int max = 0, pos = 0;
        len = strlen(str);
        for (int i = 2; i<n; i++)
        if (height[i]>max)
        {
            if (0 <= sa[i - 1] && sa[i - 1] < len&&len < sa[i])
                max = height[i];
            if (0 <= sa[i] && sa[i] < len&&len < sa[i - 1])
                max = height[i];
        }
        cout << max << endl;
    }
    return 0;
}