Problem:
Carpenters' Language

International Carpenters Professionals Company (ICPC) is a top construction company with a lot of expert carpenters.
What makes ICPC a top company is their original language.

The syntax of the language is simply given in CFG as follows:

S -> SS | (S) | )S( | ε

In other words, a right parenthesis can be closed by a left parenthesis and a left parenthesis can be closed by a right parenthesis in this language.

Alex, a grad student mastering linguistics, decided to study ICPC's language.
As a first step of the study, he needs to judge whether a text is well-formed in the language or not.
Then, he asked you, a great programmer, to write a program for the judgement.

Alex's request is as follows: You have an empty string S in the beginning, and construct longer string by inserting a sequence of '(' or ')' into the string.
You will receive q queries, each of which consists of three elements (p, c, n), where p is
the position to insert, n is the number of characters to insert and c is either '(' or ')', the character to insert.
For each query, your program should insert c repeated by n times into the p-th position of S from the beginning.
Also it should output, after performing each insert operation, "Yes" if S is in the language and "No" if S is not in the language.

Please help Alex to support his study, otherwise he will fail to graduate the college.

Input

The first line contains one integer q (1 \leq q \leq 10^5) indicating the number of queries, follows
q lines of three elements, p_i, c_i, n_i, separated by a single space (1 \leq i \leq q, c_i = '(' or ')',
0 \leq p_i \leq length of S before i-th query, 1 \leq n \leq 2^{20}).
It is guaranteed that all the queries in the input are valid.

Output

For each query, output "Yes" if S is in the language and "No" if S is not in the language.

Sample Input 1

3
0 ( 10
10 ) 5
10 ) 5

Output for the Sample Input 1

No
No
Yes

Sample Input 2

3
0 ) 10
10 ( 5
10 ( 5

Output for the Sample Input 2

No
No
Yes

Sample Input 3

3
0 ( 10
10 ) 20
0 ( 10

Output for the Sample Input 3

No
No
Yes

Solution in JAVA (judge verdict: Accepted)

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.NoSuchElementException;
import java.util.Scanner;

public class Main {
	int Q;
	long r,l;
	public void solve() {
		Q = nextInt();
		r = 0;
		l = 0;
		for(int i = 0;i < Q;i++){
			long p = nextLong();
			String c = next();
			int n = nextInt();
			
			if(c.equals("(")){
				r += n;
			}else{
				l += n;
			}
			
			if(r == l){
				out.println("Yes");
			}else{
				out.println("No");
			}
		}
	}
 
	public static void main(String[] args) {
		out.flush();
		new Main().solve();
		out.close();
	}
		/* Input */
	private static final InputStream in = System.in;
	private static final PrintWriter out = new PrintWriter(System.out);
	private final byte[] buffer = new byte[2048];
	private int p = 0;
	private int buflen = 0;

	private boolean hasNextByte() {
		if (p < buflen)
			return true;
		p = 0;
		try {
			buflen = in.read(buffer);
		} catch (IOException e) {
			e.printStackTrace();
		}
		if (buflen <= 0)
			return false;
		return true;
	}

	public boolean hasNext() {
		while (hasNextByte() && !isPrint(buffer[p])) {
			p++;
		}
		return hasNextByte();
	}

	private boolean isPrint(int ch) {
		if (ch >= '!' && ch <= '~')
			return true;
		return false;
	}

	private int nextByte() {
		if (!hasNextByte())
			return -1;
		return buffer[p++];
	}

	public String next() {
		if (!hasNext())
			throw new NoSuchElementException();
		StringBuilder sb = new StringBuilder();
		int b = -1;
		while (isPrint((b = nextByte()))) {
			sb.appendCodePoint(b);
		}
		return sb.toString();
	}

	public int nextInt() {
		return Integer.parseInt(next());
	}

	public long nextLong() {
		return Long.parseLong(next());
	}

	public double nextDouble() {
		return Double.parseDouble(next());
	}
}