spoj705

题解:

后缀数组求出height

然后ans=所有串-所有height

代码:

#include<bits/stdc++.h> 
using namespace std;  
const int N=10005;
int t,ans,n,m,wa[N],wb[N],wsf[N],wv[N],sa[N],rank[N],height[N],s[N],a[N];  
char str[N],str1[N],str2[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 *x=wa,*y=wb;  
    for (int i=0;i<m;i++)wsf[i]=0;  
    for (int i=0;i<n;i++)wsf[x[i]=r[i]]++;  
    for (int i=1;i<m;i++)wsf[i]+=wsf[i-1];  
    for (int i=n-1;i>=0;i--)sa[--wsf[x[i]]]=i;  
    for (int p=1,j=1;p<n;j*=2,m=p)  
     {  
         p=0;
        for (int i=n-j;i<n;i++)y[p++]=i;  
        for (int i=0;i<n;i++)
         if (sa[i]>=j)y[p++]=sa[i]-j;  
        for (int i=0;i<n;i++)wv[i]=x[y[i]];  
        for (int i=0;i<m;i++)wsf[i]=0;  
        for (int i=0;i<n;i++)wsf[wv[i]]++;  
        for (int i=1;i<m;i++)wsf[i]+=wsf[i-1];  
        for (int i=n-1;i>=0;i--)sa[--wsf[wv[i]]]=y[i];  
        swap(x,y);x[sa[0]]=0;p=1;
        for (int 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 j,k=0;  
    for (int i=1;i<=n;i++)rank[sa[i]]=i;  
    for (int i=0;i<n;i++)  
     {   
        if (k)k--;  
        else k=0;  
        j=sa[rank[i]-1];  
        while (r[i+k]==r[j+k])k++;  
        height[rank[i]]=k;  
     }  
}  
int main()  
{  
    scanf("%d",&t);  
    while (t--)  
     {  
        scanf("%s",str);  
        int len=strlen(str);  
        for (int i=0;i<len;i++)s[i]=str[i];  
        s[len]=0;  
        getsa(s,sa,len+1,300);  
        getheight(s,len);  
        int ans=(1+len)*len/2;  
        for (int i=2;i<=len;i++)ans-=height[i];  
        printf("%d
",ans);  
     }  
}  
原文地址:https://www.cnblogs.com/xuanyiming/p/8544174.html