Replace all pi(recursion)

#1

#include
#include
using namespace std;
string replace_pi(string s,int n,int i){
if(n<=1){
return s;
}
string res=replace_pi(s,n-1,i+1);
if(s[i-1]==‘p’&&s[i]==‘i’)
{
res=res.substr(0,i)+“3.14”+res.substr(i+2);
}
else
return res;
}
int main(){
int t;
cin>>t;
for(int i=0;i<t;i++){
string s;
getline(cin,s);
int n=s.length();
cout<<replace_pi(s,n,0);
}
}
whats wrong in this code?

#2

Hi @tishya_goyal, there are some errors in your code like

  1. string res=replace_pi(s,n-1,i+1); here you are passing string as a whole but actually it should be replace_pi(s.substr(i+1,n),n-1,i+1) ,
  2. you have to consider base cases like i=0 as in case of i=0 ,s[i-1] will compute to s[-1] which is an invalid index and lead to runtime error

here check this simple code : - https://ide.codingblocks.com/s/213799
i have discussed the code along with the logic
In case of any doubt feel free to ask :slight_smile:
If you got the answer then mark your doubt as resolved

#3

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