Codeforces Round #535 (Div. 3) C. Nice Garland(暴力)

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

int main()
{
	int len;
	cin>>len;
	string str;
	cin>>str;
	string a[6] = {"RGB", "RBG", "GRB", "GBR", "BRG","BGR"};
	int ans = 0x3f3f3f3f , xx = -1;
	for(int i=0;i<6;i++){
		int cnt = 0;
		for(int j=0;j<len;j++){
			if(a[i][j%3] != str[j]) cnt ++;
		}
		if(cnt < ans){
			ans = cnt;
			xx = i;
		}
	}
	cout<<ans<<endl;
	for(int i=0;i<len;i++){
		cout<<a[xx][i%3];
	}
	puts("");
  return 0;
}