有点复杂的ZOJ 2081

先用BFS计算出所需要的最小步数,然后在BFS计算没有遇到炸弹的路径条数
计算炸弹路径稍微麻烦了一点.
这题是我写的比较痛苦的一个了,花了大概3个半小时(汗),调试时连文件输出都 用上了,唉,果然不擅长调DFS啊.
代码:

#include <iostream>
#include <queue>
#include <cstring>/*
#include <fstream>*/
using namespace std;
struct node
{
    int x,y,cnt;
};
char map[11][11];
char mapcp[11][11];
int route,cnt,mines;
node t,tt,start,end;
int boom;/*
fstream outfile;*/

void chuandfs(int x,int y,int l)
{
    int a,b;
    if(l==cnt)
    {
        /*outfile << "*** x: " << x << "   ";
        outfile << "y: " << y << "   ";
        outfile << "l: " << l << endl;*/
        if(x==end.x&&y==end.y)
        {
            if(boom>0)
            {
                mines++;
            }
            route++;
        }
        return;
    }
    /*outfile << endl;
    outfile << "x: " << x << "   ";
    outfile << "y: " << y << "   ";
    outfile << "boom: " << boom << "   ";
    outfile << "mines: " << mines << "   ";
    outfile << "route: " << route << "   ";
    outfile << "l: " << l << endl;*/

    /*for(int i=0;i<6;++i)
    {
            for(int j=0;j<10;++j)
                outfile << mapcp[i][j];
            outfile << endl;
    }*/
    a = x+1;b = y;
    if(mapcp[a][b]!='#')
    {
        if(mapcp[a][b]=='M')
            boom++;
        mapcp[a][b] = '#';
        chuandfs(a,b,l+1);
        mapcp[a][b] = map[a][b];
        if(mapcp[a][b]=='M')
            boom--;
    }
    a = x-1;b = y;
    if(mapcp[a][b]!='#')
    {
        if(mapcp[a][b]=='M')
            boom++;
        mapcp[a][b] = '#';
        chuandfs(a,b,l+1);
        mapcp[a][b] = map[a][b];
        if(mapcp[a][b]=='M')
            boom--;
    }
    a = x;b = y+1;
    if(mapcp[a][b]!='#')
    {
        if(mapcp[a][b]=='M')
            boom++;
        mapcp[a][b] = '#';
        chuandfs(a,b,l+1);
        mapcp[a][b] = map[a][b];
        if(mapcp[a][b]=='M')
            boom--;
    }
    a = x;b = y-1;
    if(mapcp[a][b]!='#')
    {
        if(mapcp[a][b]=='M')
            boom++;
        mapcp[a][b] = '#';
        chuandfs(a,b,l+1);
        mapcp[a][b] = map[a][b];
        if(mapcp[a][b]=='M')
            boom--;
    }
}
int main()
{    
    /*
    outfile.open("out");*/
    int x;char ct;
    int m,n,i,j,ccc=1;bool ff,path;
    queue<node> rer;    
    cin >> x;
    while(x--)
    {
        cin >> n >> m;
        getchar();
        for(i=0;i<n;++i)
        {
            for(j=0;j<m;++j)
            {
                ct = getchar();
                if(ct=='\n')
                    ct = getchar();
                map[i][j] = ct;
                if(ct=='S')
                {
                    start.x = i;
                    start.y = j;
                    start.cnt = 0;
                }
                else if(ct=='T')
                {
                    end.x = i;
                    end.y = j;
                }
            }
        }
        for(i=0;i<n;++i)
            for(j=0;j<m;++j)
                mapcp[i][j] = map[i][j];
        // bfs
        mapcp[start.x][start.y] = '#';
        rer.push(start);ff = false;
        while(!rer.empty())
        {
            t = rer.front();
            rer.pop();
            if(t.x==end.x&&t.y==end.y)
            {
                ff = true;
                break;
            }
            tt = t;
            if(map[tt.x+1][tt.y]!='#')
            {
                tt.x++;
                tt.cnt++;
                rer.push(tt);
                map[tt.x][tt.y] = '#';
            }
            tt = t;
            if(map[tt.x-1][tt.y]!='#')
            {
                tt.x--;
                tt.cnt++;
                rer.push(tt);
                map[tt.x][tt.y] = '#';
            }
            tt = t;
            if(map[tt.x][tt.y+1]!='#')
            {
                tt.y++;
                tt.cnt++;
                rer.push(tt);
                map[tt.x][tt.y] = '#';
            }
            tt = t;
            if(map[tt.x][tt.y-1]!='#')
            {
                tt.y--;
                tt.cnt++;
                rer.push(tt);
                map[tt.x][tt.y] = '#';
            }
        }
        while(!rer.empty())
            rer.pop();
        if(ff==false)
        {
            cout << "Mission #" << ccc++ << ":" << endl;
            cout << "Mission Impossible." << endl << endl;
            continue;
        }
        for(i=0;i<n;++i)
            for(j=0;j<m;++j)
                map[i][j] = mapcp[i][j];
        cnt = t.cnt;
        route = mines = 0;boom = 0;
        mapcp[start.x][start.y] = '#';
        chuandfs(start.x,start.y,0);
        cout << "Mission #" << ccc++ << ":" << endl;
        if(mines==route)
        {
            cout << "Mission Impossible." << endl << endl;
        }
        else
        {
            double result = ((double)(route-mines))/route*100;
            printf("The probability for the spy to get to the telegraph transmitter is %.2lf",result);
            cout << "%.\n\n";
        }
        /*outfile.close();*/
    }
    return 0;
}