有两个字符串a,b。假设a="ab",b="cd",判断字符串c="acbd"是属于a、b的组合。满足组合后a、b的内部顺序均不变。

#include<iostream>
#include<string>
using namespace std;

int check(string a,string b,string c)
{
int lena=a.length();
int lenb=b.length();
int lenc=c.length();
if(lenc!=(lena+lenb))return 0;

if(a=="")
{
if(b==""&&c=="")return 1;
else if(b!=""&&c!="")
{
for(int i=0;i<lenb;i++)
{
if(b.at(i)!=c.at(i))return 0;
}
return 1;
}
else return 0;
}
else if(b=="")
{
if(c=="")return 0;
else
{
for(int i=0;i<lena;i++)
{
if(a.at(i)!=c.at(i))return 0;
}
return 1;
}
}
else
{
if(a.at(0)==c.at(0)&&b.at(0)!=c.at(0))
{
return check(a.substr(1),b,c.substr(1));
}
else if(b.at(0)==c.at(0)&&a.at(0)!=c.at(0))
{
return check(a,b.substr(1),c.substr(1));
}
else if(b.at(0)==a.at(0)&&a.at(0)==c.at(0))
{
check(a.substr(1),b,c.substr(1));
return check(a,b.substr(1),c.substr(1));
}
else return 0;
}

}

int main()
{
string a="abc";
string b="cd";
string c="abcdc";
cout<<check(a,b,c)<<endl;

system("pause");
return 0;
}