1108D - Diverse Garland - CodeForces Solution

#include <bits/stdc++.h>
#define ll long long

using namespace std;
const int N = 2e5+9, OO = 0x3f3f3f3f;

int n, ans;
string s;

void solveIt(){
	cin>>n>>s;
	for(int i=0 ; i<n-1 ; i++){
		if(s[i]==s[i+1]){
			ans++;
			if(s[i]!='B' && s[i+2]!='B')
				s[i+1]='B';
			if(s[i]!='G' && s[i+2]!='G')
				s[i+1]='G';
			if(s[i]!='R' && s[i+2]!='R')
				s[i+1]='R';
		}
	}
	cout<<ans<<endl<<s;
}

int32_t main(){
	ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
	int tc = 1;
	//cin >> tc;
	while (tc--) solveIt();
}