MaximumSubarraySum.java

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.InputMismatchException;
import java.util.List;

public class B {
	static InputStream is;
	static PrintWriter out;
	static String INPUT = "";

	static void solve()
	{
		for(int T = ni();T >= 1;T--){
			int n = ni();
			long m = nl();
			long[] a = new long[n+1];
			for(int i = 0;i < n;i++){
				a[i+1] = (a[i] + nl()) % m;
			}
			long[][] as = new long[n+1][];
			for(int i = 0;i < n+1;i++){
				as[i] = new long[]{a[i], i};
			}
			Arrays.sort(as, new Comparator<long[]>() {
				public int compare(long[] a, long[] b) {
					return Long.compare(a[0], b[0]);
				}
			});
			long[] asv = new long[n+1];
			int[] ias = new int[n+1];
			for(int i = 0;i < n+1;i++){
				ias[(int)as[i][1]] = i;
				asv[i] = as[i][0]*2;
			}

			LST lst = new LST(n+2);

			long max = 0;
			for(int i = 0;i < n+1;i++){
				if(i > 0){
					int wh = Arrays.binarySearch(asv, a[i]*2+1);
					wh = -wh-1;
					int nex = lst.next(wh);
					if(nex == -1){
						nex = lst.next(0);
					}
					max = Math.max(max, (a[i]-as[nex][0]+m)%m);
				}
				lst.set(ias[i]);
			}
			out.println(max);
		}
	}

	public static class LST {
		public long[][] set;
		public int n;
//		public int size;

		public LST(int n) {
			this.n = n;
			int d = 1;
			for(int m = n;m > 1;m>>>=6, d++);

			set = new long[d][];
			for(int i = 0, m = n>>>6;i < d;i++, m>>>=6){
				set[i] = new long[m+1];
			}
//			size = 0;
		}

		// FIXME
		public LST set(int l, int r)
		{
			if(0 <= l && l <= r && r <= n){
				setRange(r);
				unsetRange(l-1);
			}
			return this;
		}

		public LST setRange(int r)
		{
			for(int i = 0;i < set.length;i++, r>>>=6){
				for(int j = 0;j < r>>>6;j++){
					set[i][j] = -1;
				}
				set[i][r>>>6] |= (1L<<r+1)-1;
			}
			return this;
		}

		public LST unsetRange(int r)
		{
			if(r >= 0){
				for(int i = 0;i < set.length;i++, r>>>=6){
					for(int j = 0;j < r>>>6;j++){
						set[i][j] = 0;
					}
					set[i][r>>>6] &= ~((1L<<r+1)-1);
				}
			}
			return this;
		}

		public LST set(int pos)
		{
			if(pos >= 0 && pos < n){
//				if(!get(pos))size++;
				for(int i = 0;i < set.length;i++, pos>>>=6){
					set[i][pos>>>6] |= 1L<<pos;
				}
			}
			return this;
		}

		public LST unset(int pos)
		{
			if(pos >= 0 && pos < n){
//				if(get(pos))size--;
				for(int i = 0;i < set.length && (i == 0 || set[i-1][pos] == 0L);i++, pos>>>=6){
					set[i][pos>>>6] &= ~(1L<<pos);
				}
			}
			return this;
		}

		public boolean get(int pos)
		{
			return pos >= 0 && pos < n && set[0][pos>>>6]<<~pos<0;
		}

		public int prev(int pos)
		{
			for(int i = 0;i < set.length && pos >= 0;i++, pos>>>=6, pos--){
				int pre = prev(set[i][pos>>>6], pos&63);
				if(pre != -1){
					pos = pos>>>6<<6|pre;
					while(i > 0)pos = pos<<6|63-Long.numberOfLeadingZeros(set[--i][pos]);
					return pos;
				}
			}
			return -1;
		}

		public int next(int pos)
		{
			for(int i = 0;i < set.length && pos>>>6 < set[i].length;i++, pos>>>=6, pos++){
				int nex = next(set[i][pos>>>6], pos&63);
				if(nex != -1){
					pos = pos>>>6<<6|nex;
					while(i > 0)pos = pos<<6|Long.numberOfTrailingZeros(set[--i][pos]);
					return pos;
				}
			}
			return -1;
		}

		private static int prev(long set, int n)
		{
			long h = Long.highestOneBit(set<<~n);
			if(h == 0L)return -1;
			return Long.numberOfTrailingZeros(h)-(63-n);
		}

		private static int next(long set, int n)
		{
			long h = Long.lowestOneBit(set>>>n);
			if(h == 0L)return -1;
			return Long.numberOfTrailingZeros(h)+n;
		}

		@Override
		public String toString()
		{
			List<Integer> list = new ArrayList<Integer>();
			for(int pos = next(0);pos != -1;pos = next(pos+1)){
				list.add(pos);
			}
			return list.toString();
		}
	}

	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];
	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)); }
}