[Topcoder] srm197

Divii lev2

 

First, define the offset in eight directions. Take the first coordinate of the array pieces and obtain the eight offset coordinates. The result must be a subset of these coordinates, if the coordinates threaten other coordinates of the array, the result array is added. The order of the question must be arranged, as long as the offset is defined in an ordered order, which saves explicit sorting.

# Include <iostream> <br/> # include <string> <br/> # include <vector> <br/> # include <cmath> <br/> # include <sstream> <br/> # include <iterator> <br/> using namespace STD; </P> <p> # define ABS (x) (x <0? -X: X) </P> <p> const int xoffset [8] = {-2,-2,-1,-1, 1, 1, 2, 2 }; <br/> const int yoffset [8] = {-1, 1,-2, 2,-2, 2,-1, 1 }; </P> <p> class generalchess {<br/> PRIVATE: </P> <p> int canthreaten (const int curx, const int Cury, <br/> const int posx, const int posy) {<br/> If (ABS (curx-posx) = 1 & ABS (Cury-Posy) = 2 <br/> | ABS (curx-posx) = 2 & ABS (Cury-Posy) = 1) <br/> return 1; <br/> else <br/> Return 0; <br/>}</P> <p> Public: <br/> vector <string> attackpositions (vector <string> pieces) {<br/> vector <string> res; <br/> int X, Y; <br/> char t; </P> <p> istringstream SS (pieces. at (0); <br/> SS> x> T> Y; </P> <p> for (INT I = 0; I <8; I ++) {<br/> int curx = x + xoffset [I]; <br/> int Cury = Y + yoffset [I]; <br/> Int J = 1; <br/> for (j = 1; j <pieces. size (); j ++) {<br/> istringstream OSS (pieces. at (J); <br/> int posx, Posy; <br/> OSS> posx> T> posy; <br/> If (! Canthreaten (curx, Cury, posx, Posy) {<br/> break; <br/>}</P> <p >}< br/> If (j = pieces. size () {<br/> ostringstream RESS; <br/> RESS <curx <',' <Cury; <br/> res. push_back (RESS. STR (); <br/>}< br/> return res; <br/>}< br/> }; </P> <p> int main () <br/> {<br/> generalchess GC; <br/> vector <string> VEC; <br/> Vec. push_back ("0, 0"); </P> <p> vector <string> res = GC. attackpositions (VEC); </P> <p> copy (res. begin (), Res. end (), <br/> ostream_iterator <string> (cout, ""); <br/> cout <Endl; </P> <p> Vec. clear (); <br/> Vec. push_back ("2, 1"); <br/> Vec. push_back ("-1,-2"); <br/> res = GC. attackpositions (VEC); <br/> copy (res. begin (), Res. end (), <br/> ostream_iterator <string> (cout, ""); <br/> cout <Endl; </P> <p> return 0; <br/>}

Of course, if you want to explicitly sort, you can also:

Bool compare (string a, string B) {<br/> int ax, ay; <br/> int BX, by; <br/> char T; </P> <p> istringstream SS (a); <br/> SS> ax> T> ay; </P> <p> SS. clear (); <br/> SS. STR (B); <br/> SS> BX> T>; </P> <p> If (ax <BX <br/> | Ax = Bx & ay <by) <br/> return true; <br/> else <br/> return false; <br/>}</P> <p> int main () <br/>{< br/> vector <string> VEC; <br/> Vec. push_back ("0, 0"); <br/> Vec. push_back ("2, 1"); <br/> Vec. push_back ("1, 2"); </P> <p> sort (VEC. begin (), VEC. end (), compare); </P> <p> copy (VEC. begin (), VEC. end (), <br/> ostream_iterator <string> (cout, ""); <br/> cout <Endl; </P> <p> return 0; <br/>}< br/>