BFS(最短路) HDOJ 4308 Saving Princess claire_

/************************************************
* Author        :Running_Time
* Created Time  :2015-8-22 11:56:55
* File Name     :I.cpp
************************************************/

#include <cstdio>
#include <algorithm>
#include <iostream>
#include <sstream>
#include <cstring>
#include <cmath>
#include <string>
#include <vector>
#include <queue>
#include <deque>
#include <stack>
#include <list>
#include <map>
#include <set>
#include <bitset>
#include <cstdlib>
#include <ctime>
using namespace std;

#define lson l, mid, rt << 1
#define rson mid + 1, r, rt << 1 | 1
typedef long long ll;
typedef pair<int, int> P;
const int N = 5e3 + 10;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
int dx[4] = {-1, 1, 0, 0};
int dy[4] = {0, 0, -1, 1};
struct Node	{
int x, y, step;
};
Node t[N/10];
char maze

;
bool vis

;
int n, m, cost, tot;
int sx, sy, ex, ey;

bool judge(int x, int y)	{
if (x < 1 || x > n || y < 1 || y > m || vis[x][y] || maze[x][y] == '#')	return false;
return true;
}

int BFS(void)	{
//	memset (vis, false, sizeof (vis));
//  memset (d, INF, sizeof (d));
for (int i=1; i<=n; ++i)	{
for (int j=1; j<=m; ++j)	vis[i][j] = false;
}
vis[sx][sy] = true;
queue<Node> Q;	Q.push (Node {sx, sy, 0});

while (!Q.empty ())	{
Node u = Q.front ();	Q.pop ();
for (int i=0; i<4; ++i)	{
int tx = u.x + dx[i], ty = u.y + dy[i];
if (!judge (tx, ty))	continue;
vis[tx][ty] = true;
if (maze[tx][ty] == 'C')	{
return u.step;
}
if (maze[tx][ty] == 'P')	{
for (int i=1; i<=tot; ++i)	{
t[i].step = u.step;
Q.push (t[i]);
vis[t[i].x][t[i].y] = true;
}
}
else	{
Q.push (Node {tx, ty, u.step + 1});
}
}
}

return -1;
}

int main(void)    {
while (scanf ("%d%d%d", &n, &m, &cost) == 3)	{
sx = sy = 0;	ex = ey = 0;	tot = 0;
for (int i=1; i<=n; ++i)	{
scanf ("%s", maze[i] + 1);
for (int j=1; j<=m; ++j)	{
if (maze[i][j] == 'Y')	{
sx = i, sy = j;
} else if (maze[i][j] == 'C')	{
ex = i, ey = j;
} else if (maze[i][j] == 'P')	{
t[++tot].x = i;	t[tot].y = j;
}
}
}

int res = BFS ();
if (res != -1)	{
printf ("%d\n", res * cost);
} else	puts ("Damn teoy!");
}

return 0;
}