DDPC1B_full.java

import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.Map;
import java.util.Map.Entry;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;
 
public class Main {
	static long INF=Long.MAX_VALUE/4-1;
	public static void main(String[] args) {
 
		FastScanner sc=new FastScanner();
		long n=sc.nextInt();
		int count=0;
		int prev=-1;
		int now=-1;
		Map<Integer, Set<Integer>> data=new TreeMap<Integer, Set<Integer>>();
		for(int i=0;i<n;i++){
			Integer tmp=sc.nextInt();
			int constant=i;
			data.merge(tmp,new TreeSet<Integer>(Arrays.asList(constant)),(val,num)->{
				val.add(constant);
				return val;
			});
		}
 
		for(Entry<Integer, Set<Integer>> entry:data.entrySet()){
			prev= now;
			if(entry.getValue().size()==1){
				now=entry.getValue().iterator().next();
				if(prev>now)count++;
			}else{
				Integer min=entry.getValue().stream()
						.min((a,b)->a.compareTo(b)).get();
				if(prev>min){
					count++;
					final int fval = prev;
					now=entry.getValue().stream()
							.filter(a->(fval>a))	//小さい中で
							.max((a,b)->a.compareTo(b)).get();	//最大をとる
				}else{
					now=entry.getValue().stream()
							.max((a,b)->a.compareTo(b)).get();
				}
			}
		}
		if(now!=0)count++;
		System.out.println(count);
	}
 
 
}
class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
    private boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
    private void skipUnprintable() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++;}
    public boolean hasNext() { skipUnprintable(); return hasNextByte();}
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    public int nextInt() {
        if (!hasNext()) throw new NoSuchElementException();
        int n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
}