hdu1044 bfs+dfs

哎 搜索太差了额~~~~

#include <iostream>#include <string.h>#include <stdio.h>#include <queue>using namespace std;char map[55][55];int val[60];int d[60][60];int step[60][60];bool vis[60][60];bool mark[60];int xx[4]={0,1,0,-1};int yy[4]={1,0,-1,0};int w,h,l,m;int maxx;int sval;queue<int> q;void bfs(int x,int y,int num){    while(!q.empty())q.pop();    memset(vis,false,sizeof(vis));    memset(step,0,sizeof(step));    int s=x*w+y;    vis[x][y]=true;    step[x][y]=0;    q.push(s);    while(!q.empty())    {        s=q.front();        q.pop();        y=s%w;        x=s/w;        int i;        for(i=0;i<4;i++)        {            int nx=x+xx[i];            int ny=y+yy[i];            if(nx<0||nx>=h||ny<0||ny>=w)                continue;            if(vis[nx][ny]||map[nx][ny]=='*')                continue;            vis[nx][ny]=true;            step[nx][ny]=step[x][y]+1;            if(map[nx][ny]=='@')                d[num][0]=step[nx][ny];            else if(map[nx][ny]=='<')                d[num][m+1]=step[nx][ny];            else if(map[nx][ny]>='A'&&map[nx][ny]<='J')                d[num][map[nx][ny]-'A'+1]=step[nx][ny];            q.push(nx*w+ny);        }    }}void dfs(int now,int v,int time){    if(time>l)        return ;    if(maxx==sval)        return ;    if(now>m)    {        if(v>maxx)            maxx=v;        return ;    }    int i;    for(i=0;i<=m+1;i++)    {        if(!d[now][i]||mark[i]==true)            continue;        mark[i]=true;        dfs(i,v+val[i],time+d[now][i]);        mark[i]=false;    }}int main(){    int t;    scanf("%d",&t);    int cas;    for(cas=1;cas<=t;cas++)    {        scanf("%d%d%d%d",&w,&h,&l,&m);        int i,j;        memset(d,0,sizeof(d));        sval=0;        for(i=1;i<=m;i++)        {            scanf("%d",&val[i]);            sval+=val[i];        }        val[0]=val[m+1]=0;        for(i=0;i<h;i++)            scanf("%s",map[i]);        for(i=0;i<h;i++)        {            for(j=0;j<w;j++)            {                if(map[i][j]=='@')                    bfs(i,j,0);                else if(map[i][j]=='<')                    bfs(i,j,m+1);                else if(map[i][j]>='A'&&map[i][j]<='J')                    bfs(i,j,map[i][j]-'A'+1);            }        }        memset(mark,false,sizeof(mark));        maxx=-1;        mark[0]=true;        dfs(0,0,0);        if(cas!=1)            printf("\n");        printf("Case %d:\n",cas);        if(maxx==-1)            printf("Impossible\n");        else            printf("The best score is %d.\n",maxx);    }    return 0;}