BNU-truchet tiling-Search

Question:

A pattern is provided for you to output the connected area of the pattern.

Solution:

This question is troublesome. It is a BFS or DFS search. It is troublesome to mark the direction. I decided not to try again as I watched Yan yufang finish.

#include <iostream>#include <cstdio>#include<queue>#include <cstring>#include<cmath>#include <algorithm>#include <iostream>const double PI=acos(-1)/4.0;const double eps=1e-8;using namespace std;int m,n,Q;int grid[101][101], map[444][444];int dir[4][2]={{0,0},{0,1},{1,1},{1,0}};int dir2[4][2]={{-1,0},{0,1},{1,0},{0,-1}};int vis[433][433];void init(){    for(int i=1;i<=m;i++)    {        for(int j=1;j<=n;j++)        {            if(grid[i][j]==1)            {                map[i*2][j*2]=0;                map[i*2-1][j*2]=2;                map[i*2][j*2-1]=-2;                map[i*2-1][j*2-1]=0;            }            else            {                map[i*2][j*2]=-1;                map[i*2-1][j*2]=0;                map[i*2][j*2-1]=0;                map[i*2-1][j*2-1]=1;            }        }    }}bool check(int x,int y){    if(x<=0||y<=0||x>2*m||y>2*n||vis[x][y])return false;    return true;}void dfs(int u,int v,int f,double &ans){    vis[u][v]=1;    if(map[u][v]!=0)    {        if(map[u][v]==1)        {            if(f==0)            {                ans+=1-PI;                if(check(u,v+1))                dfs(u,v+1,1,ans);            }            else if(f==1)            {                ans+=PI;                if(check(u-1,v))                dfs(u-1,v,0,ans);            }            else if(f==2)            {                ans+=PI;                if(check(u,v-1))                dfs(u,v-1,3,ans);            }            else if(f==3)            {                ans+=1-PI;                if(check(u+1,v))                dfs(u+1,v,2,ans);            }        }        else if(map[u][v]==-1)        {             if(f==0)            {                ans+=PI;                if(check(u,v+1))                dfs(u,v+1,1,ans);            }            else if(f==1)            {                ans+=1-PI;                if(check(u-1,v))                dfs(u-1,v,0,ans);            }            else if(f==2)            {                ans+=1-PI;                if(check(u,v-1))                dfs(u,v-1,3,ans);            }            else if(f==3)            {                ans+=PI;                if(check(u+1,v))                dfs(u+1,v,2,ans);            }        }         else if(map[u][v]==2)        {             if(f==0)            {                ans+=1-PI;                if(check(u,v-1))                dfs(u,v-1,3,ans);            }            else if(f==1)            {                ans+=1-PI;                if(check(u+1,v))                dfs(u+1,v,2,ans);            }            else if(f==2)            {                ans+=PI;                if(check(u,v+1))                dfs(u,v+1,1,ans);            }            else if(f==3)            {                ans+=PI;                if(check(u-1,v))                dfs(u-1,v,0,ans);            }        }        else if(map[u][v]==-2)        {             if(f==0)            {                ans+=PI;                if(check(u,v-1))                dfs(u,v-1,3,ans);            }            else if(f==1)            {                ans+=PI;                if(check(u+1,v))                dfs(u+1,v,2,ans);            }            else if(f==2)            {                ans+=1-PI;                if(check(u,v+1))                dfs(u,v+1,1,ans);            }            else if(f==3)            {                ans+=1-PI;                if(check(u-1,v))                dfs(u-1,v,0,ans);            }        }        return;    }    ans+=1.0;    int x,y;    for(int i=0;i<4;i++)    {        x=u+dir2[i][0];        y=v+dir2[i][1];        if(check(x,y))        {            dfs(x,y,i,ans);        }    }}void solve(int x,int y){    int u,v,flag=0;    double ans=0;    memset(vis,0,sizeof(vis));    for(int i=0;i<4;i++)    {        u=x+dir[i][0];        v=y+dir[i][1];        if(u<=0||u>2*m)continue;        if(v<=0||v>2*n)continue;        if(i%2==0&&abs(map[u][v])==2)flag=1;        if(i%2==1&&abs(map[u][v])==1)flag=1;        if(flag)break;        if(check(u,v))        {            dfs(u,v,i,ans);        }    }    if(flag)puts("0.0000");    else printf("%.4lf\n",ans+eps);}char str[140];int main(){    int T,a,b;    scanf("%d",&T);    for(int ca=1;ca<=T;ca++)    {        printf("Case %d:\n",ca);        scanf("%d%d\n",&m,&n);        for(int i=1;i<=m;i++)        {            scanf("%s",str+1);            for(int j=1;j<=n;j++)            {                grid[i][j]=str[j]-'0';            }        }        init();        scanf("%d",&Q);        while(Q--)        {            scanf("%d%d",&a,&b);            solve(a,b);        }    }    return 0;}