Prefix Inversions

problem id:--https://www.codechef.com/LTIME48/problems/PREFINVS


code:--

#include<iostream>
using namespace std;
int main()
{
string str;
cin>>str;
int l=str.length()-1,count=0;
char ch;
while(l>=0 && str[l]=='0')
{
--l;
}
if(l>=0)
do
{
if(str[l]=='0')
++count,ch=str[l];
else
++count,ch=str[l];
while(l>=0 && str[l]==ch)
{
--l;
}
}while(l>=0);
cout<<count<<'\n';
return 0;
}