"BZOJ1031" character encryption cipher (suffix array)

Test instructions: A string with a length of 2n (copied and pasted) is sorted from small to large, and the last letter of each of them is printed sequentially.

n<=100000

Idea: Bare SA, template really hard back

P Party has to write C + + style

1 varCh:Array[0..300000] ofChar;2A,X,Y,WC,WD,SA:Array[0..300000] ofLongint;3 N,i,m:longint;4 Tmp:char;5  6 functionCMP (A,b,l:longint): boolean;7 begin8Exit ((Y[a]=y[b]) and(y[a+l]=y[b+l]));9 End;Ten   One procedureSwapvarx,y:longint); A varT:longint; - begin -T:=x; X:=y; y:=T; the End; -   - procedureGetsa; - varI,j,p:longint; + begin -   fori:=0  toN-1  Do +  begin Ax[i]:=A[i]; at Inc (Wc[a[i]); -  End; -   fori:=1  toM Dowc[i]:=wc[i-1]+Wc[i]; -   fori:=n-1 Downto 0  Do -  begin - Dec (wc[x[i]]); insa[wc[x[i]]]:=i; -  End; to   +j:=1; p:=1; -   whileP<n Do the  begin *p:=0; $    forI:=n-j toN-1  DoPanax Notoginseng   begin -y[p]:=I; Inc (P); the   End; +    fori:=0  toN-1  Do A    ifSa[i]>=j Then beginY[p]:=sa[i]-j; Inc (P);End; the// fori:=0  toN-1  DoWriteln (Y[i]); +    fori:=0  toN-1  Dowd[i]:=X[y[i]]; -    fori:=0  toM Dowc[i]:=0; $    fori:=0  toN-1  DoInc (Wc[wd[i]); $    fori:=1  toM Dowc[i]:=wc[i-1]+Wc[i]; -    fori:=n-1 Downto 0  Do -   begin the Dec (wc[wd[i]]); -sa[wc[wd[i]]]:=Y[i];Wuyi   End; the   -    fori:=0  toN Doswap (x[i],y[i]); Wu   -p:=1; x[sa[0]]:=0; About    fori:=1  toN-1  Do $   begin -    ifCMP (sa[i-1],SA[I],J) Thenx[sa[i]]:=p-1 -     Else beginX[sa[i]]:=p; Inc (P);End; -   End; A   +j:=j*2; them:=p; -  End; $ End; the   the   the begin theAssign (input,'bzoj1031r.in'); Reset (input); -Assign (output,'Bzoj1031r.out'); Rewrite (output); in   while  notEoln Do the  begin the read (TMP); About Inc (n); thech[n]:=tmp; the  End; the   fori:=1  toN Doa[i-1]:=Ord (Ch[i]); +   forI:=n toN2-1  Doa[i]:=a[i-n]; -n:=n*2+1; m:= -; the Getsa;Bayi   fori:=1  toN-1  Do the   ifsa[i]< (n>>1) Then the   begin -    ifsa[i]=0  ThenWrite (Chr (a[n-2])) -     ElseWrite (Chr (a[sa[i]-1])); the   End; the close (input); the close (output); the   -   the End.

"BZOJ1031" character encryption cipher (suffix array)