Tex Quotes : Problem No. 272

My submitted solution :-

#include<iostream>
#include<string>

using namespace std;

int main()
{
string str;

int i,j,t=0;
while(getline(cin,str))
{
for(i=0;i<str.length();i++)
{
if(str[i]=='"' && (t+1)%2==1)
{
str=str+str[str.length()-1];
for(j=str.length();j>i;j--)
{
str[j]=str[j-1];
}
str[i]=str[i+1]='`';
t++;
}
else if(str[i]=='"' && (t+1)%2==0)
{
str=str+str[str.length()-1];
for(j=str.length();j>i;j--)
{
str[j]=str[j-1];
}
str[i]=str[i+1]='\'';
t++;
}
}
cout<<str<<endl;
}

return 0;
}

Comment for better algorithm or any query you have.
Run Time = 0.020