hdoj 4198 Quick out of the Harbour 优先队列 + bfs

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>

using namespace std;

const int N = 509;

struct node {
int x, y, val;
node () {}
node (int tx, int ty, int tval) {
x = tx;
y = ty;
val = tval;
}
bool operator < (const node &x) const {
return val > x.val;
}
};

priority_queue<node> pq;
int dir[4][2] = {{-1,0},{1,0},{0,-1},{0,1}};
bool vis

;
char map

;
int h, w, d, ans;

void bfs() {
node t,tmp;
while (!pq.empty()) {
t = pq.top();
pq.pop();
if (t.x == 0 || t.x == w-1 || t.y == 0 || t.y == h-1) {
ans = t.val;
break;
}
int i, dx, dy;
for (i = 0; i < 4; ++i) {
tmp = t;
dx = tmp.x + dir[i][0];
dy = tmp.y + dir[i][1];
if (dx>=0 && dx<w && dy>=0 && dy<h && !vis[dy][dx] && map[dy][dx]!='#') {
vis[dy][dx] = 1;
tmp.x = dx;
tmp.y = dy;
if (map[dy][dx] == '.')
tmp.val += 1;
else
tmp.val += d+1;
pq.push(tmp);

}
}
}
}

int main()
{
int t;
scanf("%d", &t);
while (t--) {
node s;
while (!pq.empty()) pq.pop();
memset(vis, 0, sizeof(vis));
ans = 0;
scanf("%d %d %d", &h, &w, &d);
int i, j;
for (i = 0; i < h; ++i) {
scanf("%s", map[i]);
for (j = 0; j < w; ++j) {
if (map[i][j] == 'S') {
s.x = j;
s.y = i;
s.val = 0;
pq.push(s);
vis[i][j] = 1;
}
}
}
bfs();
printf("%d\n", ans+1);
}
return 0;
}