POJ-2513 colored sticks undirected Euclidean path determination + String hash

Given many sticks, the two ends have different colors, and asked if there is such a combination to connect all the sticks to the beginning and end.

Solution: this problem times out when using map to process strings, so I wrote a string hash for interpolation modulo. You only need to determine whether the graph is connected to an odd number or not, and the odd number of vertices cannot appear.

CodeAs follows:

# Include <iostream> # Include <Cstdlib> # Include <Cstring> # Include <Cstdio> # Include <Algorithm> # Include <Map> # Include < String > # Include <Vector>Using  STD: vector; typedef unsigned  Long   Long  Int64;  Const   Int MoD = 250007  ;  Const Int64 T = 37  ;  Char Sa [ 15 ], Sb [ 15  ]; Int DEG [ 500005  ];  Int   Set [ 500005  ];  Int Head [ 250010  ]; Int64 _ POW [  15  ]; Vector < Int > V;  Struct  Edge { Int  Tag, next; int64 key;} e [  500005  ];  Int  Idx, tag;  Int Find ( Int  X ){  Return   Set [X] = x = Set [X]? X: Find ( Set  [X]);}  Void Merge (Int A, Int  B ){  Set [A] = B ;}  Void Insert (int64 key, Int  TG ){  Int Pos = Key % MOD; E [idx]. Key = Key; E [idx]. Tag = TG; E [idx]. Next = Head [POS]; head [POS] = Idx ++;} Int64 getkey (  Char  STR []) {int64 key = 0  ;  Int Len = Strlen (STR );  For ( Int I = 0 ; I <Len; ++ I) {key + = (STR [I]- '  A  ' )*_ POW [I];}  Return  Key ;}  Void Hash ( Char  STR []) {int64 key = Getkey (STR); insert (Key, tag ++ );}  Int   Get ( Char  STR []) {int64 key = Getkey (STR );  Int Pos = Key %MOD;  For ( Int I = head [POS]; I! =- 1 ; I = E [I]. Next ){  If (E [I]. Key = Key ){  Return  E [I]. Tag ;}}  Return - 1  ;}  Int  Main (){ Int OK = 0  ;  For ( Int I = 0 ; I < 500000 ; ++ I ){  Set [I] = I;} _ POW [  0 ] = 1  ;  For ( Int I = 1 ; I <= 10 ; ++ I) {_ POW [I] = T * _ POW [I- 1  ];} Memset (Head,  0xff , Sizeof  (Head ));  While (Scanf ( "  % S % s  " , SA, Sb )! = EOF ){  If (Get (SA) =- 1  ) {Hash (SA );}  If ( Get (SB) =- 1  ) {Hash (SB );}  Int A = Get (SA), B = Get  (SB ); ++ Deg [a], ++ DEG [B]; merge (find (A), find (B ));}  For (Int I = 0 ; I <tag; ++ I ){  If ( Set [I] = I ){ ++ OK ;}  If (Deg [I] & 1  ) {V. push_back (I );}}  If (OK! = 1 && OK) {puts ( "  Impossible  "  );  Return   0  ;}  Else   If (V. Size ()> 2  ) {Puts (  "  Impossible  "  );}  Else  {Puts ( "  Possible  "  );}  Return   0  ;}