【BZOJ4199】品酒大会
构造出后缀数组，算出height数组，按height从大到小排序，依次用并查集合并。
我维护了正、负的最大、次大、最小值，不知道他们只维护最大值是怎么弄的...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 | #include <cstdio>#include <cstring>#include <algorithm>using namespace std;typedef long long LL;const int maxn=300010;const LL inf=~0ull>>1;char s[maxn];LL a[maxn];int sa[maxn],rank[maxn],h[maxn];LL ansa[maxn],ansb[maxn];int n;int c[maxn],temp1[maxn],temp2[maxn];void Build_SA(){ int i,m=128,*x=temp1,*y=temp2; for (i=0;i<=m;i++) c[i]=0; for (i=1;i<=n;i++) c[x[i]=s[i]]++; for (i=1;i<=m;i++) c[i]+=c[i-1]; for (i=n;i;i--) sa[c[x[i]]--]=i; for (int k=1;k<=n;k<<=1) { int p=0; for (i=n-k+1;i<=n;i++) y[++p]=i; for (i=1;i<=n;i++) if (sa[i]>k) y[++p]=sa[i]-k; for (i=0;i<=m;i++) c[i]=0; for (i=1;i<=n;i++) c[x[y[i]]]++; for (i=1;i<=m;i++) c[i]+=c[i-1]; for (i=n;i;i--) sa[c[x[y[i]]]--]=y[i]; swap(x,y);p=1;x[sa[1]]=p; for (i=2;i<=n;i++) x[sa[i]]=(y[sa[i]]==y[sa[i-1]] && y[sa[i]+k]==y[sa[i-1]+k])?p:++p; if (p>=n) break; m=p; }}void Get_Height(){ for (int i=1;i<=n;i++) rank[sa[i]]=i; for (int i=1,x=0;i<=n;i++) { if (x) x--; int j=sa[rank[i]-1]; while (i+x<=n && j+x<=n && s[i+x]==s[j+x]) x++; h[rank[i]]=x; }}struct Info {int id,h;}I[maxn];bool cmp(const Info &a,const Info &b) {return a.h>b.h;}LL submax1[maxn],submax2[maxn],negmax1[maxn],negmax2[maxn],submin[maxn],negmin[maxn],tot[maxn];int f[maxn];int Find(int x) {return f[x]==x?x:f[x]=Find(f[x]);}void Update(int x,int y,int o){ int fx=Find(x),fy=Find(y); f[fx]=fy; ansa[o]-=tot[fx]*(tot[fx]-1)/2; ansa[o]-=tot[fy]*(tot[fy]-1)/2; tot[fy]+=tot[fx]; ansa[o]+=tot[fy]*(tot[fy]-1)/2; LL v1=submax1[fx],v2=submax1[fy],v3=submax2[fx],v4=submax2[fy]; if (v1>v2) submax1[fy]=v1,submax2[fy]=max(v2,max(v3,v4)); else submax1[fy]=v2,submax2[fy]=max(v1,max(v3,v4)); v1=negmax1[fx],v2=negmax1[fy],v3=negmax2[fx],v4=negmax2[fy]; if (v1<v2) negmax1[fy]=v1,negmax2[fy]=min(v2,min(v3,v4)); else negmax1[fy]=v2,negmax2[fy]=min(v1,min(v3,v4)); submin[fy]=min(submin[fy],submin[fx]); negmin[fy]=max(negmin[fy],negmin[fx]); if (submax1[fy]!=-inf && submax2[fy]!=-inf && ansb[o]<submax1[fy]*submax2[fy]) ansb[o]=submax1[fy]*submax2[fy]; if (negmax1[fy]!=inf && negmax2[fy]!=inf && ansb[o]<negmax1[fy]*negmax2[fy]) ansb[o]=negmax1[fy]*negmax2[fy]; if (submin[fy]!=inf && negmin[fy]!=-inf && ansb[o]<submin[fy]*negmin[fy]) ansb[o]=submin[fy]*negmin[fy];}void Init(){ scanf("%d",&n); scanf("%s",s+1); for (int i=1;i<=n;i++) scanf("%lld",&a[i]); Build_SA(); Get_Height();}void Work(){ for (int i=0;i<=n;i++) { I[i].id=i; I[i].h=h[i]; f[i]=i; submax1[i]=submax2[i]=negmin[i]=-inf; negmax1[i]=negmax2[i]=submin[i]=inf; if (i) if (a[i]>0) submax1[i]=submin[i]=a[i];else negmax1[i]=negmin[i]=a[i]; tot[i]=1; ansb[i]=-inf; } tot[0]=0; ansb[n+1]=-inf; sort(I+1,I+1+n,cmp); for (int i=n,w=1;i>=0;i--) { ansa[i]=ansa[i+1]; ansb[i]=ansb[i+1]; while (w<=n && I[w].h==i) Update(sa[I[w].id-1],sa[I[w].id],i),w++; }}void Print(){ for (int i=0;i<n;i++) if (ansa[i]) printf("%lld %lld\n",ansa[i],ansb[i]); else printf("0 0\n");}int main(){ Init(); Work(); Print(); return 0;} |
评论 (0)
