COJ 1259: 跳跳

BFS，直接入队即可。

# include <cstdio>

# include <queue>

# include <cstring>



using namespace std;



# define N 100 + 5



int n;

char g[N][N];

char vis[N][N];



struct pos{int x, y, d;};



pos st;

queue <pos> Qst[10];



const int dx[] = {0,0,1,-1};

const int dy[] = {1,-1,0,0};



int bfs(void)

{

    queue <pos> Q;

    Q.push(st);

    vis[st.x][st.y] = 1;

    while (!Q.empty())

    {

        pos cur = Q.front(); Q.pop();

        for (int i = 0; i < 4; ++i)

        {

            pos nst;

            nst.x = cur.x + dx[i];

            nst.y = cur.y + dy[i];

            if (1<=nst.x&&nst.x<=n && 1<=nst.y&&nst.y<=n && !vis[nst.x][nst.y])

            {

                vis[nst.x][nst.y] = 1;

                char ch = g[nst.x][nst.y];

                if (ch == 'E') return cur.d+1;

                if (ch == '1') continue;

                if (ch == '0') nst.d=cur.d+1, Q.push(nst);

                else if ('2'<=ch&&ch<='9')

                {

                    pos nnst;

                    while (!Qst[ch-'0'].empty())

                    {

                        nnst = Qst[ch-'0'].front(); Qst[ch-'0'].pop();

                        vis[nnst.x][nnst.y] = 1;

                        nnst.d = cur.d + 1;

                        Q.push(nnst);

                    }

                }

            }

        }

    }

    return -1;

}



void read(void)

{

    pos tmp;

    for (int i = 2; i <= 9; ++i)

    {

        while (!Qst[i].empty()) Qst[i].pop();

    }

    for (int i = 1; i <= n; ++i)

    {

        scanf("%s", g[i]+1);

        memset(vis[i]+1, 0, sizeof(char)*n);

        for (int j = 1; j <= n; ++j)

        {

            char ch = g[i][j];

            if ('2'<=ch&&ch<='9')

            {

                tmp.x = i, tmp.y = j;

                Qst[ch-'0'].push(tmp);

            }

            else if (ch=='S')

            {

                st.x = i, st.y = j;

                st.d = 0;

            }

        }

    }

}



void solve(void)

{

    int ans = bfs();

    if (ans == -1)

        puts("Oh No!");

    else 

        printf("%d\n", ans);

}



int main()

{

    while (~scanf("%d", &n))

    {

        read();

        solve();

    }

    

    return 0;

}

/**/