Topcoder SRM646 div1 600 bfs + pruning

Topcoder SRM646 div1 600 bfs + pruning

Because there are only 47 blocks, bfs is carried out in a small range, that is, in the range of-50 <= x <= 50,-50 <= y <= 50, and then try to let the point to the right, maximum record value.

#include #include 
 
  #include 
  
   #include 
   
    #include 
    
     #include 
     
      #include 
      
       #include 
       
        #include 
        #include 
         
          #include 
          
           #pragma comment(linker,"/STACK:1024000000");#define EPS (1e-6)#define LL long long#define ULL unsigned long long#define _LL __int64#define INF 0x3f3f3f3f#define Mod 1000000007using namespace std;struct P{ int x,y,k;};queue
           
 q;map
            
             ,int> M;class TheGridDivOne{public : int find(vector 
             
               x, vector 
              
                y, int k) { q.push((P){0,0,0}); M.insert( pair
               
                ,int> (pair
                
                 (0,0),0)); P f,s; int i , n; n = x.size(); int Max = 0; map
                 
                  ,int>::iterator it; while(q.empty() == false) { f = q.front(); q.pop(); if(k-f.k+f.x <= Max) continue; Max = max(Max,f.x); it = M.find(pair
                  
                   (f.x,f.y)); if(it->second < f.k) continue; int U = Mod,D = -Mod,L = -Mod,R = Mod; s = f; for(i = 0; i < n; ++i) { if(x[i] == s.x && y[i] > s.y) U = min(U,y[i]); if(x[i] == s.x && y[i] < s.y) D = max(D,y[i]); if(y[i] == s.y && x[i] > s.x) R = min(R,x[i]); if(y[i] == s.y && x[i] < s.x) L = max(L,x[i]); } s.y = f.y,s.x = min(f.x+k-f.k,R-1),s.k = f.k+s.x-f.x; it = M.find(pair
                   
                    (s.x,s.y)); if(it == M.end()) { q.push(s); M.insert( pair
                    
                     ,int> (pair
                     
                      (s.x,s.y),s.k)); } else if(it->second > s.k) { q.push(s); it->second = s.k; } for(i = f.x-1; i > max(f.x-2,L); --i) { s.x = i,s.y = f.y,s.k = f.k + f.x-i; it = M.find( pair
                      
                       (s.x,s.y) ); if(s.k > k) break; if(it == M.end()) { M.insert( pair
                       
                        ,int> (pair
                        
                         (s.x,s.y),s.k)); q.push(s); } else if(it->second > s.k) { it->second = s.k; q.push(s); } } for(i = f.y+1; i < min(f.y+2,U); ++i) { s.x = f.x,s.y = i,s.k = f.k + i-f.y; if(s.k > k) break; it = M.find( pair
                         
                          (s.x,s.y)); if(it == M.end()) { M.insert( pair
                          
                           ,int> (pair
                           
                            (s.x,s.y),s.k)); q.push(s); } else if(it->second > s.k) { it->second = s.k; q.push(s); } } for(i = f.y-1; i > max(f.y-2,D); --i) { s.x = f.x,s.y = i,s.k = f.k + f.y-i; if(s.k > k) break; it = M.find( pair
                            
                             (s.x,s.y)); if(it == M.end()) { M.insert( pair
                             
                              ,int> (pair
                              
                               (s.x,s.y),s.k)); q.push(s); } else if(it->second > s.k) { it->second = s.k; q.push(s); } } if(f.k <= 50) { for(i = f.x+1; i < min(f.x+2,R); ++i) { s.x = i,s.y = f.y,s.k = f.k + i-f.x; it = M.find( pair
                               
                                (s.x,s.y) ); if(s.k > k) break; if(it == M.end()) { M.insert( pair
                                
                                 ,int> (pair
                                 
                                  (s.x,s.y),s.k)); q.push(s); } else if(it->second > s.k) { it->second = s.k; q.push(s); } } } } return Max; }};