Don't Know Why Judge is Outputting Incorrect Answer When Local Program Works

Hello. I am trying to solve the problem 266A. I tested my code and it works fine locally. However, the judge is giving wrong answer. I don't know what is the cause of this. Also, when I outputted the value of R after breaking inner while loop, it's somehow 36 when it should theoretically be strictly less than value of n(for one of test case "RRG" that's length 3). I wasn't facing this issue when I ran code locally. What can be the problem? Here it is:

#include <iostream>
using namespace std; 
 
void solve(){
    int n;
    cin >> n; 
    cout << "Value of n: " << n << '\n';
    string s; 
    cin >> s; 
    int R, L = 0; 
    int ans = 0; 
    while(L < n - 1){
        //encountered contiguous block of adjacent stones of same color => extend window far as possible of mathcing color! 
        if(s[L] == s[L+1]){
            cout << "Found contiguous block!" << '\n'; 
            while(R < n && s[R] == s[L]){
                R++; 
            }
            cout << "Cur Left Boundary: " << L << '\n'; 
            cout << "End Right Boundary: " << R << '\n'; 
            //R - L is number of stones adjacent of same color=> need to remove 1 less than it to satisfy requirement of problem => 
            //no two adjacent stones same color! 
            ans += R - L - 1; 
            cout << "Value of ans after adding: " << ans << '\n';
            L = R; 
        } else{
            L++;
            R++;
        }
    }
    cout << ans; 
}
int main(){
    solve(); 
}

Thanks! Much help appreciated.