ZOJ 1649 BFS

来源：互联网发布：java系统开发编辑：程序博客网时间：2024/05/18 13:06
#include <cstdio>#include <queue>#include <cstring>using namespace std;const int INF = 0x3f3f3f3f;const int maxn = 2E2 + 10;const int dir[4][2] = {{0, 1}, {0, -1}, {1, 0}, { -1, 0}};struct Node{    int x, y;    int step;    bool operator<(const Node &oth)const    {        return step > oth.step;    }};Node cur, Next;char mp[maxn][maxn];int n, m, Arrival[maxn][maxn], Startx, Starty;int BFS(){    priority_queue<Node>Q;    cur.x = Startx; cur.y = Starty; cur.step = 0;    Arrival[Startx][Starty] = 0;    Q.push(cur);    while (!Q.empty())    {        cur = Q.top(); Q.pop();        if (mp[cur.x][cur.y] == 'a') return cur.step;        for (int i = 0; i < 4; i++)        {            Next.x = cur.x + dir[i][0];            Next.y = cur.y + dir[i][1];            Next.step = cur.step + 1;            if (mp[Next.x][Next.y] == 'x') Next.step++;            if (mp[Next.x][Next.y] != '#' && Next.step < Arrival[Next.x][Next.y])            {                Arrival[Next.x][Next.y] = Next.step;                Q.push(Next);            }        }    }    return 0;}int main(int argc, char const *argv[]){    while (~scanf("%d%d", &n, &m))    {        for (int i = 0; i <= m + 1; i++)            mp[0][i] = mp[n + 1][i] = '#';        for (int i = 1; i <= n; i++)        {            scanf("%s", mp[i] + 1);            mp[i][0] = mp[i][m + 1] = '#';            for (int j = 1; j <= m; j++)                if (mp[i][j] == 'r') Startx = i, Starty = j;        }        memset(Arrival, INF, sizeof(Arrival));        int ans = BFS();        if (ans) printf("%d\n", ans);        else printf("Poor ANGEL has to stay in the prison all his life.\n");    }    return 0;}
这题简直有鬼。。。
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