Special String Again

#include <bits/stdc++.h>
using namespace std;

int main()
{
    int n,c,i=0,j,ans=0;
    cin>>n;

    string s;
    cin>>s;

    int same_char_count[n]={0};

    while(i<n) {
        j=i+1,c=1;
        while(j<n && s[i]==s[j]) {
            ++j,++c;
        }

        //total substrings which have all same char(s)
        ans+=(c*(c+1))>>1;
        same_char_count[i]=c;
        i=j;
    }

    for(j=1;j<n-1;++j) {
        if(s[j]==s[j-1]) {
            same_char_count[j] = same_char_count[j-1];
        }

        //odd length substr(s) which has middle element diiferent
        if(s[j-1]==s[j+1] && s[j]!=s[j-1]) {
            ans += min(same_char_count[j-1], same_char_count[j+1]);
        }
    }
    cout<<ans<<endl;

    return 0;
}