Submission #487222

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Source Code Expand

/*
 * e.cc: E: 
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_H = 30;
const int MAX_W = 30;
const int DN = 8;
const int DBITS = 1 << DN;
const int DMASK = DBITS - 1;

const int INF = 1 << 30;

const int dxs[] = {1, 0, -1, 0}, dys[] = {0, -1, 0, 1};

/* typedef */

struct Stat {
  int x, y, bits, d;
  Stat() {}
  Stat(int _x, int _y, int _bits, int _d): x(_x), y(_y), bits(_bits), d(_d) {}
  bool operator>(const Stat& s) const { return d > s.d; }
  void print() {printf("Stat: x=%d, y=%d, bits=%02x, d=%d\n", x, y, bits, d);}
};

/* global variables */

int flds[MAX_H][MAX_W];
int dists[MAX_H][MAX_W][DBITS], ds0[MAX_H][MAX_W][DBITS];
Stat prvs[MAX_H][MAX_W][DBITS];
int bnums[DBITS];

/* subroutines */

/* main */

int main() {
  for (int bits = 0; bits < DBITS; bits++) {
    bnums[bits] = 0;
    for (int i = 0; i < DN; i++)
      if (bits & (1 << i)) bnums[bits]++;
  }

  int h, w;
  cin >> h >> w;

  memset(flds, 0, sizeof(flds));
  int sx, sy, gx, gy;
  
  for (int y = 0; y < h; y++) {
    string line;
    cin >> line;
    for (int x = 0; x < w; x++) {
      if (line[x] == '#')
	flds[y][x] = -1;
      else if (line[x] == '^')
	sx = x, sy = y;
      else if (line[x] == '$')
	gx = x, gy = y;
      else if (line[x] >= 'a' && line[x] <= 'h')
	flds[y][x] = line[x] - 'a' + 1;
      else if (line[x] >= 'A' && line[x] <= 'H')
	flds[y][x] = line[x] - 'A' + 1 + DN;
    }
  }

  for (int y = 0; y < h; y++)
    for (int x = 0; x < w; x++)
      for (int bits = 0; bits < DBITS; bits++)
	dists[y][x][bits] = ds0[y][x][bits] = INF;
  dists[gy][gx][0] = ds0[gy][gx][0] = 0;
  prvs[gy][gx][0] = Stat(gx, gy, 0, -1);
  
  priority_queue<Stat,vector<Stat>,greater<Stat> > q;
  q.push(Stat(gx, gy, 0, 0));
  
  while (! q.empty()) {
    Stat u = q.top(); q.pop();
    if (dists[u.y][u.x][u.bits] != u.d) continue;
    //u.print();

    if (u.x == sx && u.y == sy && u.bits == 0) break;

    for (int di = 0; di < 4; di++) {
      int vx = u.x + dxs[di], vy = u.y + dys[di];
      if (vx >= 0 && vx < w && vy >= 0 && vy < h && flds[vy][vx] >= 0) {
	int vbits = u.bits, vf = flds[vy][vx];
	int vd = u.d + 1, vd0 = ds0[u.y][u.x][u.bits] + 1;

	if (vf > DN) {
	  int k = vf - DN - 1, bk = 1 << k;
	  vbits |= bk;
	}
	else if (vf >= 1) {
	  int k = vf - 1, bk = 1 << k;
	  if (vbits & bk) {
	    Stat pu = u;
	    while (prvs[pu.y][pu.x][pu.bits].bits & bk)
	      pu = prvs[pu.y][pu.x][pu.bits];
	    vd += vd0 - ds0[pu.y][pu.x][pu.bits] + bnums[vbits];
	    vbits &= ~bk;
	  }
	}

	if (dists[vy][vx][vbits] > vd) {
	  dists[vy][vx][vbits] = vd;
	  ds0[vy][vx][vbits] = vd0;
	  q.push(Stat(vx, vy, vbits, vd));
	  prvs[vy][vx][vbits] = u;
	}
      }
    }
  }

  cout << (dists[sy][sx][0] >= INF ? -1 : dists[sy][sx][0]) << endl;

  return 0;
}

Submission Info

Judge Result