bzoj2432

被虐的体无完肤，

直接给题解地址吧：http://vfleaking.blog.163.com/blog/static/174807634201341721051604/

const maxk=1000010;
type matrix=array[1..3,1..3] of int64;
var a:array[0..maxk*6] of longint;
    first,last,b,len:array[0..maxk] of longint;
    pre:array[0..maxk] of longint;
    n,k,p,x,y,sum:int64;
    i,j:longint;
    ans,aa,bb,s:matrix;

function ni(x:int64; y:longint):int64;
  begin
    ni:=1;
    while y>0 do
    begin
      if y mod 2=1 then ni:=ni*x mod k;
      y:=y div 2;
      x:=x*x mod k;
    end;
  end;

procedure work;
  var i,d,ph:longint;
  begin
    a[1]:=1;a[2]:=1;i:=2;
    while true do
    begin
      inc(i);
      a[i]:=(a[i-1]+a[i-2]) mod k;
      if first[a[i]]=0 then first[a[i]]:=i;
      if (a[i]=1) and (a[i-1]=1) then break;
    end;
    d:=k;
    ph:=k;
    for i:=2 to trunc(sqrt(k)) do
      if d mod i=0 then
      begin
        ph:=ph div i*(i-1);
        while d mod i=0 do d:=d div i;
      end;
    if d>1 then ph:=ph div d*(d-1);

    for i:=1 to k-1 do
    begin
      pre[i]:=ni(i,ph-1);
      if int64(pre[i])*int64(i) mod k<>1 then pre[i]:=0;
    //  writeln(pre[i]);
    end;
    b[1]:=1;last[1]:=1;i:=1;
    while true do
    begin
      len[i]:=first[pre[b[i]]]-1;
      if len[i]<0 then break;
      inc(i);
      b[i]:=int64(a[len[i-1]])*b[i-1] mod k;
      if last[b[i]]>0 then break;
      last[b[i]]:=i;
    end;
    aa[1,2]:=1; aa[2,1]:=1; aa[2,2]:=1; aa[3,3]:=1;
    bb:=aa; bb[3,2]:=p-1;
  end;

operator *(a,b:matrix)c:matrix;
  var i,j,k:longint;
  begin
    for i:=1 to 3 do
      for j:=1 to 3 do
      begin
        c[i,j]:=0;
        for k:=1 to 3 do
          c[i,j]:=(c[i,j]+a[i,k]*b[k,j]) mod p;
      end;
  end;

function f(a:matrix;n:int64):matrix;
  begin
    fillchar(f,sizeof(f),0);
    f[1,1]:=1;f[2,2]:=1;f[3,3]:=1;
    while n>0 do
    begin
      if n and 1=1 then f:=f*a;
      a:=a*a;
      n:=n div 2;
    end;
  end;

begin
  readln(n,k,p);
  if n<3 then
  begin
    writeln(1);
    exit;
  end;
  work;
  ans[1,1]:=1; ans[2,2]:=1; ans[3,3]:=1;
  if n>len[1] then
  begin
    dec(n,len[1]+1);
    ans:=ans*f(aa,len[1]-2)*bb;
  end
  else begin
    ans:=ans*f(aa,n-2);
    n:=0;
  end;
  i:=2;
  while n>0 do
  begin
    if (pre[b[i]]=0) or (len[i]<0) then
    begin
      ans:=ans*f(aa,n);
      n:=0;
      break;
    end;
    if last[b[i]]<i then break;
    if n>len[i] then
    begin
      dec(n,len[i]+1);
      ans:=ans*f(aa,len[i])*bb;
    end
    else begin
      ans:=ans*f(aa,n);
      n:=0;
    end;
    inc(i);
  end;
  if n<>0 then
  begin
    j:=i;
    sum:=0;
    fillchar(s,sizeof(s),0);
    s[1,1]:=1; s[2,2]:=1; s[3,3]:=1;
    for i:=last[b[j]] to j-1 do
    begin
      inc(sum,len[i]+1);
      s:=s*f(aa,len[i])*bb;
    end;
    ans:=ans*f(s,n div sum);
    n:=n mod sum;
    i:=last[b[j]];
    while n>0 do
    begin
      if n>len[i] then
      begin
        ans:=ans*f(aa,len[i])*bb;
        dec(n,len[i]+1);
      end
      else begin
        ans:=ans*f(aa,n);
        n:=0;
      end;
      inc(i);
    end;
  end;
  writeln((ans[1,2]+ans[2,2]+ans[3,2]) mod p);
end.