CCF 201409-4 最优配餐

#include "iostream"
#include "vector"
#include "queue"

using namespace std;

int dist[1001][1001];
bool visited[1001][1001];
int width, numStore, numClient, numHole;

struct Pos {
  int x, y, val;
  Pos(int _x, int _y): x(_x), y(_y) {}
  Pos() {}
};

bool legal(int x, int y) {
  return x>=1 && y>=1 && x<=width && y<=width;
}

Pos dir[4] = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}};

int main() {
  cin >> width >> numStore >> numClient >> numHole;
  
  queue<Pos> stores;
  vector<Pos> holes, clients;
  
  Pos p;
  for(int i=0; i<numStore; i++) {
    cin >> p.x >> p.y;
    stores.push(p);
    dist[p.x][p.y] = 0;
    visited[p.x][p.y] = true;
  }
  for(int i=0; i<numClient; i++) {
    cin >> p.x >> p.y >> p.val;
    clients.push_back(p);
  }
  for(int i=0; i<numHole; i++) {
    cin >> p.x >> p.y;
    dist[p.x][p.y] = -1;
    visited[p.x][p.y] = true;
  }
  while(!stores.empty()) {
    Pos p = stores.front();
    stores.pop();
    for(int i=0; i<4; i++) {
      Pos np(p.x+dir[i].x, p.y+dir[i].y);
      if(!visited[np.x][np.y] && legal(np.x, np.y)) {
        visited[np.x][np.y] = true;
        dist[np.x][np.y] = dist[p.x][p.y] + 1;
        stores.push(np);
      }
    }
  }
  long long cost = 0;
  for(int i=0; i<numClient; i++) {
    cost += dist[clients[i].x][clients[i].y] * clients[i].val;
  }
  cout << cost;
}