Poj 3729 Facer's string (suffix array)

Question:

The number of Suffixes in string 1 and the LCP of a Suffix in string 2 are K

Train of Thought Analysis:

First, find the number of logarithm with a length of at least K.

Then find out the number of values at least k + 1.

Then subtract.

#include <cstdio>#include <iostream>#include <algorithm>#include <cstring>#include <map>#include <string>#define maxn 110005using namespace std;int str[maxn];int sa[maxn],t1[maxn],t2[maxn],c[maxn],n;void suffix(int m){    int *x=t1,*y=t2;    for(int i=0; i<m; i++)c[i]=0;    for(int i=0; i<n; i++)c[x[i]=str[i]]++;    for(int i=1; i<m; i++)c[i]+=c[i-1];    for(int i=n-1; i>=0; i--)sa[--c[x[i]]]=i;    for(int k=1; k<=n; k<<=1)    {        int p=0;        for(int i=n-k; i<n; i++)y[p++]=i;        for(int i=0; i<n; i++)if(sa[i]>=k)y[p++]=sa[i]-k;        for(int i=0; i<m; i++)c[i]=0;        for(int i=0; i<n; i++)c[x[y[i]]]++;        for(int i=0; i<m; i++)c[i]+=c[i-1];        for(int i=n-1; i>=0; i--)sa[--c[x[y[i]]]]=y[i];        swap(x,y);        p=1;        x[sa[0]]=0;        for(int i=1; i<n; i++)            x[sa[i]]=y[sa[i-1]]==y[sa[i]]&&y[sa[i-1]+k]==y[sa[i]+k]?p-1:p++;        if(p>=n)break;        m=p;    }}int rank[maxn],height[maxn];void getheight(){    int k=0;    for(int i=0; i<n; i++)rank[sa[i]]=i;    for(int i=0; i<n; i++)    {        if(k)k--;        if(!rank[i])continue;        int j=sa[rank[i]-1];        while(str[i+k]==str[j+k])k++;        height[rank[i]]=k;    }}int tmp[50005];int solve(int k,int nn){    int ans=0;    int res=0,ret=0;    for(int i=1; i<n; i++)    {        if(height[i]<k)        {            if(ret)                ans+=res;            res=ret=0;            if(sa[i]<nn)res++;            else ret++;        }        else        {            if(sa[i]<nn)res++;            else ret++;        }    }    if(ret)ans+=res;    return ans;}int main(){    int nn,mm,k;    while(scanf("%d%d%d",&nn,&mm,&k)!=EOF)    {        int top=0;        for(int i=1; i<=nn; i++)        {            scanf("%d",&tmp[i]);            tmp[i]+=2;            str[top++]=tmp[i];        }        str[top++]=1;        for(int i=1; i<=mm; i++)        {            scanf("%d",&tmp[i]);            tmp[i]+=2;            str[top++]=tmp[i];        }        str[top++]=0;        n=top;        suffix(10005);        getheight();        printf("%d\n",solve(k,nn)-solve(k+1,nn));    }    return 0;}