705 Slash Maze

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图的转化，想了N久没想出来，看了题解发现自己其实想的差不多了，但是想多了（ORZ流泪）

把图扩大两倍（就是一个斜杠占2个位置）

走8个发现，走斜对角的时候需要特判

写完一次就AC了

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int maxn = 80;
const int maxd = 222;
const int dir[8][2] = {{0,1},{0,-1},{1,0},{-1,0},{1,1},{1,-1},{-1,1},{-1,-1}};
int n,m;
int nn,mm;
char smat[maxn][maxn];
int mat[maxd][maxd];
int vis[maxd][maxd];
int aim_x,aim_y;
int ans_num;
int ans_len;
void debug(){
    for(int i = 0; i < nn; i++){
        for(int j = 0; j < mm; j++){
            printf("%d ",mat[i][j]);
        }
        puts("");
    }
}
bool judge(int x,int y,int d){
    if(d < 4) return true;
    else if(d == 4){ //1 1
        if(mat[x + 1][y] == 2 && mat[x][y + 1] == 2)
            return false;
        else
            return true;
    }
    else if(d == 5){//1 -1
        if(mat[x + 1][y] == 1 && mat[x][y - 1] == 1)
            return false;
        else
            return true;
    }
    else if(d == 6){//-1 1
        if(mat[x - 1][y] == 1 && mat[x][y + 1] == 1)
            return false;
        else
            return true;
    }
    else if(d == 7){ // -1 -1
        if(mat[x - 1][y] == 2 && mat[x][y - 1] == 2)
            return false;
        else
            return true;
    }
}
void dfs(int x,int y,int px,int py,int step){
    vis[x][y] = 1;
    for(int d = 0; d < 8; d++){
        int xx = x + dir[d][0];
        int yy = y + dir[d][1];
        if(xx >= 0 && xx < nn && yy >= 0 && yy < mm){
            if(!vis[xx][yy] && !mat[xx][yy] && judge(x,y,d)){
                dfs(xx,yy,x,y,step + 1);
                return;
            }
            else{
                if((xx != px || yy != py) && (xx == aim_x && yy == aim_y)){
                    ans_num ++;
                    ans_len = max(ans_len,step);
                    return;
                }
            }
        }
    }
    return;
}
int main(){
    int Case = 1;
    while(scanf("%d%d",&m,&n)){
        if(!n && !m) break;
        nn = n * 2;
        mm = m * 2;
        ans_num = 0;
        ans_len = -1;
        memset(mat,0,sizeof(mat));
        memset(vis,0,sizeof(vis));
        for(int i = 0; i < n; i++)
            scanf("%s",smat[i]);
        for(int i = 0,ii = 0; ii < n; i += 2,ii ++){
            for(int j = 0,jj = 0; jj < m; j += 2,jj ++){
                if(smat[ii][jj] == '\\'){
                    mat[i][j] = 1;
                    mat[i + 1][j + 1] = 1;
                }
                else if(smat[ii][jj]  == '/'){
                    mat[i + 1][j] = 2;
                    mat[i][j + 1] = 2;
                }
            }
        }
        //debug();
        for(int i = 0; i < nn; i++){
            for(int j = 0; j < mm; j++){
                if(!mat[i][j] && !vis[i][j]){
                    aim_x = i;  aim_y = j;
                    dfs(i,j,-1,-1,0);
                }
            }
        }
        printf("Maze #%d:\n",Case++);
        if(!ans_num)
            printf("There are no cycles.\n");
        else
            printf("%d Cycles; the longest has length %d.\n",ans_num,ans_len + 1);
        puts("");
    }
    return 0;
}

705 Slash Maze

标签：

原文地址：http://blog.csdn.net/u013451221/article/details/44517295