题意：求一个字符串里两个不重叠的最长重复子串
代码如下：
1 #include<cstdio> 2 #include<cstdlib> 3 #include<cstring> 4 #include<iostream> 5 using namespace std; 6 7 int sa[20010],rank[20010],y[20010],Rsort[20010]; 8 int wr[20010],a[20010],height[20010],n; 9 10 bool cmp(int k1,int k2,int ln){return wr[k1]==wr[k2] && wr[k1+ln]==wr[k2+ln];} 11 12 void get_sa(int m) 13 { 14 int i,k,p,ln; 15 16 memcpy(rank,a,sizeof(rank)); 17 18 memset(Rsort,0,sizeof(Rsort)); 19 for (i=1;i<=n;i++) Rsort[rank[i]]++; 20 for (i=1;i<=m;i++) Rsort[i]+=Rsort[i-1]; 21 for (i=n;i>=1;i--) sa[Rsort[rank[i]]--]=i; 22 23 ln=1; p=0; 24 while (p<n) 25 { 26 for (k=0,i=n-ln+1;i<=n;i++) y[++k]=i; 27 for (i=1;i<=n;i++) if (sa[i]>ln) y[++k]=sa[i]-ln; 28 for (i=1;i<=n;i++) wr[i]=rank[y[i]]; 29 30 memset(Rsort,0,sizeof(Rsort)); 31 for (i=1;i<=n;i++) Rsort[wr[i]]++; 32 for (i=1;i<=m;i++) Rsort[i]+=Rsort[i-1]; 33 for (i=n;i>=1;i--) sa[Rsort[wr[i]]--]=y[i]; 34 35 memcpy(wr,rank,sizeof(wr)); 36 p=1; rank[sa[1]]=1; 37 for (i=2;i<=n;i++) 38 { 39 if (!cmp(sa[i],sa[i-1],ln)) p++; 40 rank[sa[i]]=p; 41 } 42 m=p; ln*=2; 43 } 44 a[0]=sa[0]=0; 45 } 46 47 void get_he() 48 { 49 int i,j,k=0; 50 for (i=1;i<=n;i++) 51 { 52 j=sa[rank[i]-1]; 53 if (k) k--; 54 55 while (a[j+k]==a[i+k]) k++; 56 height[rank[i]]=k; 57 } 58 } 59 60 bool check(int k) 61 { 62 int i,maxx=0,minn=20010; 63 for(i=1;i<=n;i++) 64 { 65 if(height[i]<k) maxx=minn=sa[i]; 66 else 67 { 68 if(sa[i]>maxx) maxx=sa[i]; 69 if(sa[i]<minn) minn=sa[i]; 70 if(maxx-minn>k) return 1; 71 } 72 } 73 return 0; 74 } 75 76 int hd_work() 77 { 78 int l,r,mid,ans=0; 79 l=1;r=n; 80 while(l<=r) 81 { 82 mid=(l+r)/2; 83 if(check(mid)) 84 { 85 l=mid+1; 86 ans=mid; 87 } 88 else r=mid-1; 89 } 90 if(ans>=4) ans++; 91 else ans=0; 92 return ans; 93 } 94 95 int main() 96 { 97 int i,a1,a2; 98 while(1) 99 { 100 scanf("%d",&n); 101 if(n==0) break; 102 scanf("%d",&a1); 103 for(i=2;i<=n;i++) 104 { 105 scanf("%d",&a2); 106 a[i-1]=a2-a1+88; 107 a1=a2; 108 } 109 n--; 110 get_sa(20010); 111 get_he(); 112 printf("%d ",hd_work()); 113 } 114 }
2015-12-15 17:09:09