Language: Java

import java.util.*;
import java.util.Map.Entry;

import javax.swing.text.Segment;
import javax.xml.ws.WebEndpoint;

import java.io.*;
import java.lang.reflect.Array;
import java.math.BigInteger;

import static java.lang.Math.*;
import static java.util.Arrays.*;
import static java.util.Collections.*;

public class Main implements Runnable
{
//    static int dx[]={-1,0,1,0};
//    static int dy[]={0,-1,0,1};
    static long mod=1000000007;
    
    public static void main(String[] args) {        
        new Thread(null, new Main(), "", 200 * 1024 * 1024).start();        
    }

    public void run() {
        Reader sc = new Reader(System.in);
        PrintWriter out=new PrintWriter(System.out);

        int n=sc.nextInt();
        char c[]=sc.getCharSet();
        long r=0,g=0,b=0,ans=0;
        for (int i = 0; i < c.length; i++) {
			if(c[i]=='R')r++;
			else if(c[i]=='G')g++;
			else b++;
		}
        ans=r*g*b;
        for (int i = 1; i < c.length; i++) {
			for (int j = i; j+i < c.length; j++) {
				if(c[j-i]!=c[j] && c[j]!=c[i+j] && c[j-i]!=c[i+j])ans--;
			}
		}
    
        out.println(ans);
     	out.flush();
    }

    static void ret(String ans) {
    	System.out.println(ans);
    	System.exit(0);
    }

    static void ret(long ans) {
    	System.out.println(ans);
    	System.exit(0);
    }
    
    static boolean validpos(int x,int y,int r, int c){
        return x<r && 0<=x && y<c && 0<=y;
    }

    static void db(Object... os){
        System.err.println(Arrays.deepToString(os));
    }
}

//class P {
//	int x,y; double d;
//	P(int  x, int y, double d) {
//	  this.x=x;
//	  this.y=y;
//	  this.d=d;
//	}
//}


//class P implements Comparable<P>{
//    int i,x,r,f;
//    P(int i,int x,int r,int f) {
//    	this.i=i;
//    	this.x=x;
//    	this.r=r;
//    	this.f=f;
//    }
//
//    public int compareTo(P p){
//    	if(-this.r+p.r==0) {
//    		return -this.x+p.x;
//    	}
//        return -this.r+p.r;
//    }
//}

class Reader
{ 
    private BufferedReader x;
    private StringTokenizer st;
    
    public Reader(InputStream in)
    {
        x = new BufferedReader(new InputStreamReader(in));
        st = null;
    }
    public String nextString()
    {
        while( st==null || !st.hasMoreTokens() )
			try {
				st = new StringTokenizer(x.readLine());
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
        return st.nextToken();
    }
    public int nextInt()
    {
        return Integer.parseInt(nextString());
    }
    public int[] nextIntArray(int size) {
        int r[] = new int[size];
        for (int i = 0; i < size; i++) {
            r[i] = this.nextInt(); 
        }
        return r;
    }
    public long[] nextLongArray(int size) {
        long r[] = new long[size];
        for (int i = 0; i < size; i++) {
            r[i] = this.nextLong(); 
        }
        return r;
    }
    public char[] getCharSet() {
        return this.nextString().toCharArray();
    }    
    public long nextLong()
    {
        return Long.parseLong(nextString());
    }
    public double nextDouble() throws IOException
    {
        return Double.parseDouble(nextString());
    }
}


Compiler output:
Main.java:5: error: package javax.xml.ws does not exist
import javax.xml.ws.WebEndpoint;
                   ^
1 error