倍增算法实现后缀数组

来源：互联网发布：mac luajit 编译编辑：程序博客网时间：2024/05/01 20:48

reference：http://baike.baidu.com/view/1240197.htm

in:string out：suffix array

#include<stdio.h>#include<stdlib.h>#define maxn 100void changeabc(int* r, char* c)//将字符串转换为数字 {    int i = 0;    for(;*c != '\0';c++, i++)        if(*c <= 'Z' && *c >= 'A') r[i] = *c - 64;        else if(*c <= 'z' && *c >= 'a') r[i] = *c - 70;        else printf("error\n");    r[i] = 0;            }bool cmp(int *r, int i, int j, int l){    return r[i] == r[j] && r[i + l] == r[j + l];}void suffix_ar(int* r, int* sa, int n, int m){    int  wa[maxn], i, secondkey[maxn], rank[maxn], j, *y = secondkey, *x = rank, *t, p;        for(i = 0; i <= m; i++) wa[i] = 0;    for(i = 0; i <= n - 1; i++) wa[x[i] = r[i]]++;    for(i = 0; i <= m; i++) wa[i] += wa[i - 1];    for(i = n - 1; i >=0; i--) sa[--wa[x[i]]] = i;        for(p = 1, j = 1; p < n; j *= 2, m = p)    {        for(p = 0, i = n - 1; i >= n - j; i--, p++) y[p] = i;        for(i = 0; i < n; i++) if(sa[i] >= j) y[p++] = sa[i] - j;//second key                 for(i = 0; i <= m; i++) wa[i] = 0;        for(i = 0; i <= n - 1; i++) wa[x[y[i]]]++;        for(i = 0; i <= m; i++) wa[i] += wa[i - 1];        for(i = n - 1; i >=0; i--) sa[--wa[x[y[i]]]] = y[i];                for(x = t, x = y, y = t, x[sa[0]] = 0, i = 1, p = 1; i < n; i++)            x[sa[i]] = cmp(y, sa[i], sa[i - 1], j)?p - 1:p++;    }    }  main(){    int r[maxn], sa[maxn], i, j;    char c[100];    printf("please enter the string:");    scanf("%s", c);    for(i = 0; c[i] != '\0'; i++);    changeabc(r, c);    suffix_ar(r, sa, i + 1, 52);    printf("suffix array:");    for(j = 1; j <= i; j++)        printf("%d ", sa[j]);    printf("\n");    for(j = 1; j <= i; j++)        printf("%s\n", c + sa[j]);            system("pause");    return 0;}