HDU 5094 Maze（BFS、狀態壓縮）
Maze
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 100000/100000 K (Java/Others)
Total Submission(s): 308 Accepted Submission(s): 112
Problem Description
This story happened on the background of Star Trek.
Spock, the deputy captain of Starship Enterprise, fell into Klingon’s trick and was held as prisoner on their mother planet Qo’noS.
The captain of Enterprise, James T. Kirk, had to fly to Qo’noS to rescue his deputy. Fortunately, he stole a map of the maze where Spock was put in exactly.
The maze is a rectangle, which has n rows vertically and m columns horizontally, in another words, that it is divided into n*m locations. An ordered pair (Row No., Column No.) represents a location in the maze. Kirk moves from current location to next costs
1 second. And he is able to move to next location if and only if:
Next location is adjacent to current Kirk’s location on up or down or left or right(4 directions)
Open door is passable, but locked door is not.
Kirk cannot pass a wall
There are p types of doors which are locked by default. A key is only capable of opening the same type of doors. Kirk has to get the key before opening corresponding doors, which wastes little time.
Initial location of Kirk was (1, 1) while Spock was on location of (n, m). Your task is to help Kirk find Spock as soon as possible.
Input
The input contains many test cases.
Each test case consists of several lines. Three integers are in the first line, which represent n, m and p respectively (1<= n, m <=50, 0<= p <=10).
Only one integer k is listed in the second line, means the sum number of gates and walls, (0<= k <=500).
There are 5 integers in the following k lines, represents x
i1, y
i1, x
i2, y
i2, g
i; when g
i >=1, represents there is a gate of type gi between location (x
i1, y
i1) and (x
i2,
y
i2); when g
i = 0, represents there is a wall between location (x
i1, y
i1) and (x
i2, y
i2), ( | x
i1 - x
i2 | + | y
i1 - y
i2 |=1, 0<= g
i <=p
)
Following line is an integer S, represent the total number of keys in maze. (0<= S <=50).
There are three integers in the following S lines, represents x
i1, y
i1 and q
i respectively. That means the key type of q
i locates on location (x
i1, y
i1), (1<= q
i<=p).
Output
Output the possible minimal second that Kirk could reach Spock.
If there is no possible plan, output -1.
Sample Input
4 4 9
9
1 2 1 3 2
1 2 2 2 0
2 1 2 2 0
2 1 3 1 0
2 3 3 3 0
2 4 3 4 1
3 2 3 3 0
3 3 4 3 0
4 3 4 4 0
2
2 1 2
4 2 1
Sample Output
14
Source
2014上海全國邀請賽——題目重現（感謝上海大學提供題目）
注意鑰匙拿到就一直拿到了，門只需開一次，同一個位置可能有多把鑰匙！！
#include
#include
#include
using namespace std;
const int MAXN = 16, dx[4] = {0, 1, 0, -1}, dy[4] = {1, 0, -1, 0};
int n, m, p, k, s, go[MAXN][MAXN][MAXN][MAXN], key[MAXN][MAXN], ans;
bool visited[MAXN][MAXN][1<<10];
struct State {
int x, y, key, step;
State(int _x, int _y, int _key, int _step) : x(_x), y(_y), key(_key), step(_step) {}
};
void init() {
memset(go, -1, sizeof(go));
memset(key, 0, sizeof(key));
memset(visited, false, sizeof(visited));
ans = -1;
}
void input() {
cin >> k;
for (int i = 0; i < k; i++) {
int x1, y1, x2, y2, g;
cin >> x1 >> y1 >> x2 >> y2 >> g;
go[x1][y1][x2][y2] = go[x2][y2][x1][y1] = g;
}
cin >> s;
for (int i = 0; i < s; i++) {
int x, y, q;
cin >> x >> y >> q;
key[x][y] |= 1 << (q-1);
}
}
void work() {
queue q;
q.push(State(1, 1, 0, 0));
while (!q.empty()) {
State cur = q.front();
q.pop();
if (cur.x == n && cur.y == m) {
ans = cur.step;
return;
}
cur.key |= key[cur.x][cur.y];
for (int i = 0; i < 4; i++) {
int nx = cur.x + dx[i], ny = cur.y + dy[i];
if (nx >= 1 && nx <= n && ny >= 1 && ny <= m) {
int gate = go[cur.x][cur.y][nx][ny];
if ((gate > 0 && (cur.key & (1 << (gate-1)))) || (gate == -1)) {
if (!visited[nx][ny][cur.key]) {
visited[nx][ny][cur.key] = true;
q.push(State(nx, ny, cur.key, cur.step+1));
}
}
}
}
}
}
void output() {
cout << ans << endl;
}
int main() {
ios::sync_with_stdio(false);
while (cin >> n >> m >> p) {
init();
input();
work();
output();
}
return 0;
}
