BZOJ3393 [Usaco2009 Jan]laserphones Laser Communication

For the first time know. Originally SPFA can also write like this ... With PQ ...

Only need to directly seek the inflection point, the data small want how to engage in how to do

(Say how so bare the shortest short-circuit can not write out 233)

1 /**************************************************************2 problem:33933 User:rausen4 language:c++5 result:accepted6 time:36 Ms7 memory:1156 KB8 ****************************************************************/9  Ten#include <cstdio> One#include <cstring> A#include <algorithm> -#include <queue> -   the using namespacestd; - Const intdx[4] = {0,1,0, -1}; - Const intdy[4] = {1,0, -1,0}; - Const intN = the; + Const intINF = (int) 1e9; -   + structData { A     intx, y, to, dis; at data () {} -Dataint_x,int_y,int_t,int_d): X (_x), Y (_y), to (_t), dis (_d) {} -       -InlineBOOL operator< (ConstData &b)Const { -         returnDis >B.dis; -     } in }; -   to intN, m, ans; + intSX, SY, ex, EY; - intdis[n][n][4], w[n][n]; thePriority_queue <data>Q; *   $InlineBOOL inch(intXinty) {Panax Notoginseng     return 1<= x && x <= n &&1<= y && y <=m; - } the   + intMain () { A     intI, J; the     Charch; +scanf"%d%d", &m, &n); -      for(i =1; I <= N; ++i) $          for(j =1; J <= M; ++j) { $CH =GetChar (); -          while(ch! ='C'&& ch! ='.'&& ch! ='*') -CH =GetChar (); the         if(ch = ='*') W[i][j] =1; -         if(ch = ='C')Wuyi             if(!SX) SX = i, sy =J; the             Elseex = i, EY =J; -     } Wumemset (DIS,127/3,sizeof(DIS)); -      for(i =0; I <4; ++i) { AboutQ.push (Data (SX, SY, I,0)); $Dis[sx][sy][i] =0; -     } -       -     intx, y, K, X1, y1; A      while(!Q.empty ()) { +X1 = x = Q.top (). x, y1 = y = Q.top (). Y, k =Q.top (). to; the          while(inch(x1 + = Dx[k], y1 + dy[k]) &&!w[x1][y1] && dis[x1][y1][k] >Dis[x][y][k]) { -DIS[X1][Y1][K] =Dis[x][y][k]; $ Q.push (Data (x1, y1, K, dis[x][y][k])); the         } the          for(i =0; I <4; ++i) the             if(Dis[x][y][i] > q.top (). Dis +1) { theDis[x][y][i] = q.top (). Dis +1; - Q.push (data (x, Y, I, dis[x][y][i])); in             } the Q.pop (); the     } About      for(i =0, ans = inf; I <4; ++i) theAns =min (ans, dis[ex][ey][i]); theprintf"%d\n", ans); the     return 0; +}

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BZOJ3393 [Usaco2009 Jan]laserphones Laser Communication