hdu 1501 Zipper

#include<iostream>
#include<cstring>
using namespace std;
string a,b,c;
int flag;
int visit[201][201];
void dfs(int x,int y,int z)
{
visit[x][y]=1;
if(z==c.size()) {flag=1;return;}
if(flag) {return;}
if(a[x]==b[y]&&b[y]==c[z])
{
if(!visit[x+1][y])
{
dfs(x+1,y,z+1);
visit[x+1][y]=1;
}
if(!visit[x][y+1])
{
dfs(x,y+1,z+1);
visit[x][y+1]=1;
}
}
else if(a[x]==c[z]&&!visit[x+1][y]) dfs(x+1,y,z+1),visit[x+1][y]=1;
else if(b[y]==c[z]&&!visit[x][y+1]) dfs(x,y+1,z+1),visit[x][y+1]=1;
}
int main()
{
int s,t;
cin>>t;
for(s=1;s<=t;s++)
{
cin>>a>>b>>c;
if(c.size()!=(a.size()+b.size()))
{
cout<<"Data set "<<s<<": no"<<endl;
continue;
}
flag=0;
memset(visit,0,sizeof(visit));
dfs(0,0,0);
cout<<"Data set ";
cout<<s<<": ";
if(flag) cout<<"yes";
else cout<<"no";
cout<<endl;
}
return 0;
}