STL map

BZOJ3239

BSGS

#include <cstdio>
#include <cmath>
#include <map>
#define LL long long 
using namespace std;

  LL p,b,n;
  map <int,int> mp;

  LL qpow(LL bas,int powe,LL mo){
      LL ret=1;
      for (;powe;bas*=bas,bas%=mo){
        if (powe&1) ret*=bas,ret%=mo;
        powe=powe>>1;
    }
    return(ret);
  }

  int main(){      
      while (scanf("%lld%lld%lld",&p,&b,&n)!=EOF){
        mp.clear();
        int bl=(int)sqrt(p);LL tb,bas;
      bas=tb=qpow(b,bl,p);
      for (int i=1;i<=bl;i++){
          if (mp[bas]==0) mp[bas]=i*bl;
          bas*=tb;bas%=p;
      }
      tb=1;
      LL ans=1e9;
      for (LL i=0;i<=bl;i++){
          if (tb==n) ans=min(ans,i);
          LL t=qpow(tb,p-2,p)*n%p;
          if (mp[t]) ans=min(ans,mp[t]+i);
          tb*=b;tb%=p;
      }
      if (ans!=1e9) printf("%lld\n",ans);else printf("no solution\n");
    }
  }

a^x==b(mod\ p)\\  
得\ a^x+k*p==b\\  
设\ g=gcd(a,p)，那么\frac{b}{g}为整数\\  
得\frac{a}{g}a^{x-1}+k\frac{p}{g}=\frac{b}{g}\\  
\frac{a}{g}a^{x-1}==\frac{b}{g}(mod\ \frac{p}{g})\\  
a^{x-1}==\frac{b}{g}(\frac{a}{g})^{-1}(mod\ \frac{p}{g})\\  
a^{x’}=={b’}(mod\ {m’})\\  
其中  
x’=x-1\\  
b’=\frac{b}{g}(\frac{a}{g})^{-1}\\  
m’=\frac{p}{g}

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BZOJ2754

使用map记录AC自动机的出边

#include <cstdio>
#include <map>
using namespace std;

  int a[200001];
  
  map <int,int> mp[200001];
  int next[200001],scnt,nd[200001],des[200001],cha[200001],cnt;
  int ans1[200001],ans2[200001],quenext[200001],qnd[200001];
  int dl[200001],fail[200001],vis[200001],worktim,len[200001];
  int pool[200001],n,m;
  
  void addedge(int x,int y,int ch){
      next[++scnt]=nd[x];des[scnt]=y;cha[scnt]=ch;nd[x]=scnt;
  }

  void insert(int id){
      int len=0,t;
      scanf("%d",&t);
      for (int i=1;i<=t;i++) scanf("%d",&a[++len]);
      int po=1;
      for (int i=1;i<=len;i++){
        if (!mp[po][a[i]]) addedge(po,cnt+1,a[i]),po=mp[po][a[i]]=++cnt;else
                              po=mp[po][a[i]];
    }
    quenext[id]=qnd[po];qnd[po]=id;
  }
  
  void getfail(){
      int head,tail;
      head=1;tail=0;
      for (int p=nd[1];p;p=next[p]){
        dl[++tail]=des[p];fail[des[p]]=1;
      }
      while (head<=tail){
        for (int p=nd[dl[head]];p;p=next[p]){
          int x=fail[dl[head]],y=cha[p];
        while (x&&!mp[x][y]) x=fail[x];
        if (!x) fail[des[p]]=1;else fail[des[p]]=mp[x][y];
        dl[++tail]=des[p];    
      }    
      head++;
    }
  }
  
  void getans(int po,int id){
      for (;po;po=fail[po]){
        if (vis[po]==worktim) return;
      vis[po]=worktim;
      for (int p=qnd[po];p;p=quenext[p]){
          ans1[p]++;ans2[id]++;
      }
    }
  }
  
  void solve(int id){
      int po=1;worktim++;
      for (int i=1;i<=len[id];i++){
        int num=pool[++pool[0]];
      while (po&&!mp[po][num]) po=fail[po];
      if (po==0) po=1;else po=mp[po][num];
      getans(po,id);
    }
  }

  int main(){
      scanf("%d%d",&n,&m);
      cnt=1;pool[0]=0;
      for (int i=1;i<=n;i++){
        int t;
        scanf("%d",&t);len[i]+=t;
      for (int j=1;j<=t;j++) scanf("%d",&pool[++pool[0]]);
      len[i]++;pool[++pool[0]]=1e9;
        scanf("%d",&t);len[i]+=t;
      for (int j=1;j<=t;j++) scanf("%d",&pool[++pool[0]]);
    }pool[0]=0;
    
      for (int i=1;i<=m;i++)
        insert(i);
        
      getfail();  
    
    for (int i=1;i<=n;i++) 
      solve(i);

    for (int i=1;i<=m;i++) printf("%d\n",ans1[i]);
    for (int i=1;i<n;i++) printf("%d ",ans2[i]);
    printf("%d",ans2[n]);
  }