后缀数组 LCP--模板题

  1 #define IOS ios_base::sync_with_stdio(0); cin.tie(0);
  2 #include <cstdio>//sprintf islower isupper
  3 #include <cstdlib>//malloc  exit strcat itoa system("cls")
  4 #include <iostream>//pair
  5 #include <fstream>//freopen("C:\\Users\\13606\\Desktop\\草稿.txt","r",stdin);
  6 #include <bitset>
  7 //#include <map>
  8 //#include<unordered_map>   https://www.nitacm.com/problem_show.php?pid=585
  9 #include <vector>
 10 #include <stack>
 11 #include <set>
 12 #include <string.h>//strstr substr
 13 #include <string>
 14 #include <time.h>//srand(((unsigned)time(NULL))); Seed n=rand()%10 - 0~9;
 15 #include <cmath>
 16 #include <deque>
 17 #include <queue>//priority_queue<int, vector<int>, greater<int> > q;//less
 18 #include <vector>//emplace_back
 19 //#include <math.h>
 20 //#include <windows.h>//reverse(a,a+len);// ~ ! ~ ! floor
 21 #include <algorithm>//sort + unique : sz=unique(b+1,b+n+1)-(b+1);+nth_element(first, nth, last, compare)
 22 using namespace std;//next_permutation(a+1,a+1+n);//prev_permutation
 23 #define fo(a,b,c) for(register int a=b;a<=c;++a)
 24 #define fr(a,b,c) for(register int a=b;a>=c;--a)
 25 #define mem(a,b) memset(a,b,sizeof(a))
 26 #define pr printf
 27 #define sc scanf
 28 #define ls rt<<1
 29 #define rs rt<<1|1
 30 typedef long long ll;
 31 #define rint register int
 32 void swapp(int &a,int &b);
 33 double fabss(double a);
 34 int maxx(int a,int b);
 35 int minn(int a,int b);
 36 int Del_bit_1(int n);
 37 int lowbit(int n);
 38 int abss(int a);
 39 //const long long INF=(1LL<<60);
 40 const double E=2.718281828;
 41 const double PI=acos(-1.0);
 42 const int inf=(1<<30);
 43 const double ESP=1e-9;
 44 const int mod=(int)1e9+7;
 45 const int N=(int)2e6+10;
 46 void PR(int _[],int n)
 47 {
 48     for(int i=1;i<=n;++i)
 49         pr("%d ",_[i]);
 50     pr("\n");
 51 }
 52 char s[N],s1[N],s2[N];
 53 int a[N];
 54 int sa[N],rk[N],s_a[N],t[N];//桶的大小要为N,因为放的是rank;
 55 int height[N],h[N];//h是位置i的长度,heidgt是ranki的长度;
 56 void Init(int _[],int n)
 57 {
 58     for(rint i=0;i<=n;++i)
 59         _[i]=0;
 60 }
 61 bool cmp(int i,int j,int k)
 62 {
 63     return s_a[i]==s_a[j]&&s_a[i+k]==s_a[j+k];
 64 }
 65 void Sort(int len)
 66 {
 67     int m=30;//字符集大小;
 68     for(rint i=1;i<=len;++i) ++t[a[i]],rk[i]=a[i];
 69     for(rint i=1;i<=m;++i) t[i]+=t[i-1];
 70     for(rint i=len;i>=1;--i) sa[t[rk[i]]--]=i;
 71     for(rint k=1;k<=len;k<<=1)
 72     {
 73         int cnt=0;
 74         //按第二个rank排;
 75         for(rint i=len-k+1;i<=len;++i) s_a[++cnt]=i;
 76         for(rint i=1;i<=len;++i)if(sa[i]>k) s_a[++cnt]=sa[i]-k;
 77         //按第一个rank排;
 78         Init(t,m);
 79         for(rint i=1;i<=len;++i) ++t[rk[s_a[i]]];
 80         for(rint i=1;i<=m;++i) t[i]+=t[i-1];
 81         for(rint i=len;i>=1;--i) sa[t[rk[s_a[i]]]--]=s_a[i];
 82 
 83         swap(rk,s_a);rk[sa[1]]=cnt=1;
 84         for(rint i=2;i<=len;++i)
 85             rk[sa[i]]=cmp(sa[i],sa[i-1],k)?cnt:++cnt;
 86         if(cnt==len)break;
 87         m=cnt;
 88     }
 89     //求height数组;
 90     for(rint i=1;i<=len;++i)
 91     {
 92         h[i]=max(0,h[i-1]-1);
 93         if(rk[i]==1)continue;
 94         while(a[i+h[i]]==a[sa[rk[i]-1]+h[i]]) ++h[i];
 95     }
 96     for(rint i=1;i<=len;++i) height[i]=h[sa[i]];
 97 }
 98 
 99 int ans[N],res[N];
100 
101 int main()
102 {
103 //    freopen("D:\\Chrome Download\\testdata (2).in","r",stdin);
104     int len1,len2;
105     sc("%d%d",&len1,&len2);
106     sc("%s%s",s1+1,s2+1);
107     int len=0;
108     for(int i=len1;i>=1;--i)
109         a[++len]=s1[i]-‘a‘+1;
110     a[++len]=27;
111     for(int i=len2;i>=1;--i)
112         a[++len]=s2[i]-‘a‘+1;
113     Sort(len);
114 //    PR(height,len);
115 //    PR(sa,len);
116 //    PR(rk,len);
117     int temp=0;
118     for(int i=1;i<=len;++i)
119     {
120     //    temp=min(temp,height[i+1]);
121         if(sa[i]<=len1)
122             temp=height[i+1];
123         else
124             ans[i]=temp,temp=min(temp,height[i+1]);
125     }
126     temp=0;
127     for(int i=len;i>=1;--i)
128     {
129     //    temp=min(temp,height[i+1]);
130         if(sa[i]<=len1)
131             temp=height[i];
132         else
133             ans[i]=max(ans[i],temp),temp=min(temp,height[i]);
134     }
135 //    PR(ans,len);
136     ll Ans=0;
137     for(int i=len;i>=len1+2;--i)
138     {
139         res[i]=max(res[i+1],ans[rk[i]]);
140         Ans+=res[i];
141     }
142     pr("%lld\n",Ans);
143     return 0;
144 }
145 
146 /**************************************************************************************/
147 
148 int maxx(int a,int b)
149 {
150     return a>b?a:b;
151 }
152 
153 void swapp(int &a,int &b)
154 {
155     a^=b^=a^=b;
156 }
157 
158 int lowbit(int n)
159 {
160     return n&(-n);
161 }
162 
163 int Del_bit_1(int n)
164 {
165     return n&(n-1);
166 }
167 
168 int abss(int a)
169 {
170     return a>0?a:-a;
171 }
172 
173 double fabss(double a)
174 {
175     return a>0?a:-a;
176 }
177 
178 int minn(int a,int b)
179 {
180     return a<b?a:b;
181 }