Submission #223833

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Source Code Expand

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(), m = ni(), Q = ni();
		int[] a = na(n);
		
		int mod = 1000000007;
		int[][] dpf = new int[n+1][m+1];
		dpf[0][0] = 1;
		for(int i = 0;i < n;i++){
			int cum = 0;
			for(int j = 0;j <= m;j++){
				cum += dpf[i][j];
				if(cum >= mod)cum -= mod;
				dpf[i+1][j] = cum;
				if(j >= a[i]){
					cum -= dpf[i][j-a[i]];
					if(cum < 0)cum += mod;
				}
			}
		}
		
		int[][] dpb = new int[n+1][m+1];
		dpb[n][0] = 1;
		for(int i = n-1;i >= 0;i--){
			int cum = 0;
			for(int j = 0;j <= m;j++){
				cum += dpb[i+1][j];
				if(cum >= mod)cum -= mod;
				dpb[i][j] = cum;
				if(j >= a[i]){
					cum -= dpb[i+1][j-a[i]];
					if(cum < 0)cum += mod;
				}
			}
		}
		
		int[][] cache = new int[n][m+1];
		for(int i = 0;i < n;i++){
			Arrays.fill(cache[i], -1);
		}
		long BIG = 8L*mod*mod;
		for(int q = 0;q < Q;q++){
			int k = ni()-1, x = ni();
			if(cache[k][x] != -1){
				out.println(cache[k][x]);
			}else{
				long ret = 0;
				for(int j = 0;j <= m-x;j++){
					ret += (long)dpf[k][j] * dpb[k+1][m-x-j];
					if(ret >= BIG)ret -= BIG;
				}
				cache[k][x] = (int)(ret%mod);
				out.println(cache[k][x]);
			}
		}
	}
	
	public static void main(String[] args) throws Exception
	{
//		int n = 2000, m = 2000;
//		int q = 100000;
//		Random gen = new Random();
//		StringBuilder sb = new StringBuilder();
//		sb.append(n + " ");
//		sb.append(m + " ");
//		sb.append(q + " ");
//		for (int i = 0; i < n; i++) {
//			sb.append(m + " ");
//		}
//		for(int i = 0;i < q;i++){
//			sb.append(gen.nextInt(n)+1 + " ");
//			sb.append(1 + " ");
//		}
//		INPUT = sb.toString();
		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 boolean isSpaceChar(int c) { return !(c >= 32 && 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))){
			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)); }
}

Submission Info

Judge Result