bzoj1193

 #include<cstdio>
 #include<cstdlib>
 #include<algorithm>
 #include<queue>
 using namespace std ; 

 int d [  ] [  ] ;
 int ha ( const int x , const int y ) {
     if ( x ==  && y ==  ) return  ;
     typedef pair < int , int > p ;
     queue < p > q ;
     for ( int i =  ; i <  ; ++ i )
          for ( int y =  ; y <  ; ++ y ) d [ i ] [ y ] = -  ;
     d [  ] [  ] =  ;
     q . push ( make_pair (  ,  ) ) ;
     while ( q . size () ) {
         const p o = q . front () ; q . pop () ;
         if ( abs ( o . first -  ) >  || abs ( o . second -  ) >  ) continue ;
         const int x_ [] = {  ,  ,  ,  , - , - , - , - } ;
         const int y_ [] = {  , - ,  , - ,  , - ,  , - } ;
         for ( int i =  ; i <  ; ++ i ) {
             const int nx = o . first + x_ [ i ] ;
             const int ny = o . second + y_ [ i ] ;
             if ( nx == x +  && ny == y +  ) return d [ o . first ] [ o . second ] +  ;
             if ( d [ nx ] [ ny ] == -  ) {
                 d [ nx ] [ ny ] = d [ o . first ] [ o . second ] +  ;
                 q . push ( make_pair ( nx , ny ) ) ;
             }
         }
     }
     exit ( - ) ;
 }

 int xp , yp , xs , ys ;
 int x , y ;
 int step_cnt =  ;
 int main () {
     scanf ( "%d%d%d%d" , & xp , & yp , & xs , & ys ) ;
     x = abs ( xp - xs ) ; y = abs ( yp - ys ) ;
     while ( abs ( x ) + abs ( y ) >=  ) {
         if ( abs ( x ) >= abs ( y ) ) {
             const int step = abs ( x /  ) ;
             x -= ( ( x >  ) ? step : - step ) *  ;
             y -= ( y >  ) ? step : - step ;
             step_cnt += abs ( step ) ;
         } else {
             const int step = abs ( y /  ) ;
             x -= ( x >  ) ? step : - step ;
             y -= ( y >  ? step : - step ) *  ;
             step_cnt += abs ( step ) ;
         }
     }
     printf ( "%d\n" , step_cnt + ha ( abs ( x ) , abs ( y ) ) ) ;
     return  ;
 }

贪心+bfs