dsubseq.java

import java.io.*;
import java.util.*;

public class dsubseq
{
    private static Reader in;
    private static PrintWriter out;

    public static void main (String [] args) throws IOException {
        in = new Reader ();
        out = new PrintWriter (System.out, true);
        
        int T = in.nextInt ();
        long mod = 1000000007;
        while (T-- > 0) {
            char [] s = in.readLine().toCharArray();
            int N = s.length;
            long [] dp = new long [N + 1];
            int [] last = new int [26];
            Arrays.fill (last, -1);
            dp[0] = 1;
            for (int i = 1; i <= N; i++) {
                int k = (int)(s[i - 1] - 'A');
                dp[i] = (2 * dp[i - 1] - (last[k] == -1 ? 0 : dp[last[k] - 1]) + mod);
                while (dp[i] >= mod) dp[i] -= mod;
                last[k] = i;
            }
            out.println (dp[N]);
        }
    }
}

/** Faster input **/
class Reader {
    final private int BUFFER_SIZE = 1 << 16;private DataInputStream din;private byte[] buffer;private int bufferPointer, bytesRead;
    public Reader(){din=new DataInputStream(System.in);buffer=new byte[BUFFER_SIZE];bufferPointer=bytesRead=0;}
    public Reader(String file_name)throws IOException{din=new DataInputStream(new FileInputStream(file_name));buffer=new byte[BUFFER_SIZE];bufferPointer=bytesRead=0;}
    private byte[]buf=new byte[150000];
    public String readLine()throws IOException{int cnt=0,c;
        while((c=read())!=-1){if(c=='\n')break;buf[cnt++]=(byte)c;}return new String(buf,0,cnt);}
    public int nextInt()throws IOException{int ret=0;byte c=read();while(c<=' ')c=read();boolean neg=(c=='-');
        if(neg)c=read();do{ret=ret*10+c-'0';}while((c=read())>='0'&&c<='9');if(neg)return -ret;return ret;} 
    public long nextLong()throws IOException{long ret=0;byte c=read();while(c<=' ')c=read();boolean neg=(c=='-');
        if(neg)c=read();do{ret=ret*10+c-'0';}while((c=read())>='0'&&c<='9');if(neg)return -ret;return ret;}
    public double nextDouble()throws IOException{double ret=0,div=1;byte c=read();while(c<=' ')c=read();boolean neg=(c=='-');if(neg)c = read();do {ret=ret*10+c-'0';}while((c=read())>='0'&&c<='9');
        if(c=='.')while((c=read())>='0'&&c<='9')ret+=(c-'0')/(div*=10);if(neg)return -ret;return ret;}
    private void fillBuffer()throws IOException{bytesRead=din.read(buffer,bufferPointer=0,BUFFER_SIZE);if(bytesRead==-1)buffer[0]=-1;}
    private byte read()throws IOException{if(bufferPointer==bytesRead)fillBuffer();return buffer[bufferPointer++];}
    public void close()throws IOException{if(din==null) return;din.close();}
}