ソースコード
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;
public class Main {
static InputStream is;
static PrintWriter out;
static String INPUT = "";
static void solve() {
int n = ni();
int[] a = na(n);
Arrays.sort(a);
int[][] uc = uniqcount(a);
int m = uc.length;
long[] dp = new long[m];
dp[0] = uc[0][1];
long s = 0;
s += dp[0];
int mod = 1000000007;
for(int i = 1;i < m;i++){
dp[i] = s*uc[i][1]%mod;
s += dp[i];
s %= mod;
}
out.println(s);
}
public static int[][] uniqcount(int[] a)
{
int n = a.length;
int p = 0;
int[][] b = new int[n][];
for(int i = 0;i < n;i++){
if(i == 0 || a[i] != a[i-1])b[p++] = new int[]{a[i], 0};
b[p-1][1]++;
}
return Arrays.copyOf(b, p);
}
public static void main(String[] args) throws Exception {
long S = System.currentTimeMillis();
is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
out = new PrintWriter(System.out);
solve();
out.flush();
long G = System.currentTimeMillis();
tr(G - S + "ms");
}
private static boolean eof() {
if (lenbuf == -1)
return true;
int lptr = ptrbuf;
while (lptr < lenbuf)
if (!isSpaceChar(inbuf[lptr++]))
return false;
try {
is.mark(1000);
while (true) {
int b = is.read();
if (b == -1) {
is.reset();
return true;
} else if (!isSpaceChar(b)) {
is.reset();
return false;
}
}
} catch (IOException e) {
return true;
}
}
private static byte[] inbuf = new byte[1024];
public static int lenbuf = 0, ptrbuf = 0;
private static int readByte() {
if (lenbuf == -1)
throw new InputMismatchException();
if (ptrbuf >= lenbuf) {
ptrbuf = 0;
try {
lenbuf = is.read(inbuf);
} catch (IOException e) {
throw new InputMismatchException();
}
if (lenbuf <= 0)
return -1;
}
return inbuf[ptrbuf++];
}
private static boolean isSpaceChar(int c) {
return !(c >= 33 && c <= 126);
}
private static int skip() {
int b;
while ((b = readByte()) != -1 && isSpaceChar(b))
;
return b;
}
private static double nd() {
return Double.parseDouble(ns());
}
private static char nc() {
return (char) skip();
}
private static String ns() {
int b = skip();
StringBuilder sb = new StringBuilder();
while (!(isSpaceChar(b))) { // when nextLine, (isSpaceChar(b) && b != '
// ')
sb.appendCodePoint(b);
b = readByte();
}
return sb.toString();
}
private static char[] ns(int n) {
char[] buf = new char[n];
int b = skip(), p = 0;
while (p < n && !(isSpaceChar(b))) {
buf[p++] = (char) b;
b = readByte();
}
return n == p ? buf : Arrays.copyOf(buf, p);
}
private static char[][] nm(int n, int m) {
char[][] map = new char[n][];
for (int i = 0; i < n; i++)
map[i] = ns(m);
return map;
}
private static int[] na(int n) {
int[] a = new int[n];
for (int i = 0; i < n; i++)
a[i] = ni();
return a;
}
private static int ni() {
int num = 0, b;
boolean minus = false;
while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
;
if (b == '-') {
minus = true;
b = readByte();
}
while (true) {
if (b >= '0' && b <= '9') {
num = num * 10 + (b - '0');
} else {
return minus ? -num : num;
}
b = readByte();
}
}
private static long nl() {
long num = 0;
int b;
boolean minus = false;
while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
;
if (b == '-') {
minus = true;
b = readByte();
}
while (true) {
if (b >= '0' && b <= '9') {
num = num * 10 + (b - '0');
} else {
return minus ? -num : num;
}
b = readByte();
}
}
private static void tr(Object... o) {
if (INPUT.length() != 0)
System.out.println(Arrays.deepToString(o));
}
}