今天的一个哈密顿图 写了一个恶心的死搜

#include<string.h>
#include <stdio.h>

int m, n;
bool link[22][22];
bool v[22][22];

bool ll;
bool lll;
int bi,bj,ei,ej;
int c1;
void dfs(int i,int j)
{
    v[i][j]=1;
                if(i-1>=0 && v[i-1][j]==0 && link[i-1][j]==0)
                {
                    dfs(i-1,j);
                }
                if(j-1>=0 && v[i][j-1]==0 && link[i][j-1]==0)
                {
                    dfs(i,j-1);
                }
                if(i+1<n && v[i+1][j]==0 && link[i+1][j]==0)
                {
                    dfs(i+1,j);
                }
                if(j+1<m && v[i][j+1]==0 && link[i][j+1]==0) 
                {
                    dfs(i,j+1);
                }
}

void DFS(int i,int j)
{

    bool ss=0;
    v[i][j]=1;    
    bool vv[21][21];
    int i1,j1;
    for(i1=0;i1<n;i1++)
        for(j1=0;j1<m;j1++)
            vv[i1][j1]=v[i1][j1];

    v[i][j]=0;
        int ccc=0;
        for(i1=0;i1<n;i1++)
            for(j1=0;j1<m;j1++)
            {
                if(v[i1][j1]==0 && link[i1][j1]==0)
                {
                int cc=0;
                if(i1-1>=0 && v[i1-1][j1]==0&& link[i1-1][j1]==0)
                    cc++;
                if(j1-1>=0 && v[i1][j1-1]==0&& link[i1][j1-1]==0)
                    cc++;
                if(i1+1<n && v[i1+1][j1]==0&& link[i1+1][j1]==0)
                    cc++;
                if(j1+1<m && v[i1][j1+1]==0&& link[i1][j1+1]==0)
                    cc++;
                if(cc==1)
                {
                    ccc++;
                }
                }
            }

    bool con=1;

    if(ccc>2)    con=0;

  v[i][j]=1;
    

    for(i1=0;i1<n;i1++)
        for(j1=0;j1<m;j1++)
            if(link[i1][j1]==0 && v[i1][j1]==0)
                dfs(i1,j1);

        
    for(i1=0;i1<n;i1++)
        for(j1=0;j1<m;j1++)
            if(v[i1][j1]==0 && link[i1][j1]==0)
                con=0;

    for(i1=0;i1<n;i1++)
        for(j1=0;j1<m;j1++)
            v[i1][j1]=vv[i1][j1];
        

            if(con)
            {

                if(i-1>=0 && v[i-1][j]==0 && link[i-1][j]==0)
                {
                    for(i1=0;i1<n;i1++)
                    for(j1=0;j1<m;j1++)
                        v[i1][j1]=vv[i1][j1];

                    DFS(i-1,j);
                    ss=1;
                }
                if(j-1>=0 && v[i][j-1]==0 && link[i][j-1]==0)
                {
                    for(i1=0;i1<n;i1++)
                    for(j1=0;j1<m;j1++)
                        v[i1][j1]=vv[i1][j1];

                    DFS(i,j-1);
                    ss=1;
                }
                if(i+1<n && v[i+1][j]==0 && link[i+1][j]==0)
                {
                    for(i1=0;i1<n;i1++)
                    for(j1=0;j1<m;j1++)
                        v[i1][j1]=vv[i1][j1];

                    DFS(i+1,j);
                    ss=1;
                }
                if(j+1<m && v[i][j+1]==0 && link[i][j+1]==0) 
                {
                    for(i1=0;i1<n;i1++)
                    for(j1=0;j1<m;j1++)
                        v[i1][j1]=vv[i1][j1];

                    DFS(i,j+1);
                    ss=1;
                }

            if(ss==0)
            {
                ll=1;
                for(i1=0;i1<n;i1++)
                for(j1=0;j1<m;j1++)
                {
                    if(v[i1][j1]==0 && link[i1][j1]==0)
                    {
                        ll=0;
                        i1=n,j1=m;
                        break;
                    }
                }
                if(ll){
                    lll=1;
                    return;}
            }
            }
}


int main()
{

    while(scanf("%d%d",&n,&m)==2)
    {
        lll=0;
        ll=1;
        memset(v,0,sizeof(v));
        if(m==0 && n==0)break;
        int i, j;
        for(i=0;i<n;i++)
        {
            for(j=0;j<m;j++)
            {
                scanf("%d",&link[i][j]);
            }
        }
        ei=21,ej=21;
        c1=0;
        for(i=0;i<n;i++)
            for(j=0;j<m;j++)
            {
                if(v[i][j]==0 && link[i][j]==0)
                {
                int cc=0;
                if(i-1>=0 && v[i-1][j]==0&& link[i-1][j]==0)
                    cc++;
                if(j-1>=0 && v[i][j-1]==0&& link[i][j-1]==0)
                    cc++;
                if(i+1<n && v[i+1][j]==0&& link[i+1][j]==0)
                    cc++;
                if(j+1<m && v[i][j+1]==0 && link[i][j+1]==0)
                    cc++;
                if(cc==1)
                {
                    bi=i,bj=j;
                    c1++;
                    i=n,j=m;
                    v[bi][bj]=1;
                    break;
                }
                }
            }

        for(i=0;i<n;i++)
            for(j=0;j<m;j++)
            {
                if(v[i][j]==0 && link[i][j]==0)
                {
                int cc=0;
                if(i-1>=0 && v[i-1][j]==0&& link[i-1][j]==0)
                    cc++;
                if(j-1>=0 && v[i][j-1]==0&& link[i][j-1]==0)
                    cc++;
                if(i+1<n && v[i+1][j]==0&& link[i+1][j]==0)
                    cc++;
                if(j+1<m && v[i][j+1]==0&& link[i][j+1]==0)
                    cc++;
                if(cc==1)
                {
                    c1++;
                    ei=i,ej=j;
                    i=n,j=m;
                    break;
                }
                }
            }

            if(c1==1 || c1==2)
            {
                    memset(v,0,sizeof(v));
                    DFS(bi,bj);
            }
            if(c1==0)
            {
                for(i=0;i<n;i++)
                {
                    for(j=0;j<m;j++)
                    {
                        
                        if(link[i][j]==0)
                        {
                            memset(v,0,sizeof(v));
                            DFS(i,j);
                        }

                        if(lll==1)
                        {
                            i=n,j=m;
                            break;
                        }
                    }
                }
            }

        if(lll)
            printf("Yes\n");
        else
            printf("No\n");
    }
    return 0;
}