Problem:
MathJax.Hub.Config({ tex2jax: { inlineMath: [["$","$"], ["\\(","\\)"]], processEscapes: true }});

Areas on the Cross-Section Diagram

Your task is to simulate a flood damage.

For a given cross-section diagram, reports areas of flooded sections.

Assume that rain is falling endlessly in the region and the water overflowing from the region is falling in the sea at the both sides.
For example, for the above cross-section diagram, the rain will create floods which have areas of 4, 2, 1, 19 and 9 respectively.

Input

A string, which represents slopes and flatlands by '/', '\' and '_' respectively, is given in a line. For example, the region of the above example is given by a string "\\///\_/\/\\\\/_/\\///__\\\_\\/_\/_/\".

output

Report the areas of floods in the following format:

$A$

$k$ $L_1$ $L_2$ ... $L_k$

In the first line, print the total area $A$ of created floods.

In the second line, print the number of floods $k$ and areas $L_i (i = 1, 2, ..., k)$ for each flood from the left side of the cross-section diagram. Print a space character before $L_i$.

Constraints

$1 \leq$ length of the string $\leq 20,000$

Sample Input 1

\\//

Sample Output 1

4
1 4

Sample Input 2

\\///\_/\/\\\\/_/\\///__\\\_\\/_\/_/\

Sample Output 2

35
5 4 2 1 19 9

Solution in JAVA (judge verdict: Accepted)

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayDeque;
import java.util.Deque;
   
public class Main {
     
    public static void main(String[] args) throws IOException {
        new Main().exec();
    }
     
    public void exec() throws IOException {
        SimpleInputUtil in = new SimpleInputUtil();
        PrintWriter out = new PrintWriter(System.out);
        out.print(new SectionDiagram().analyze(in.br.readLine()));
        out.flush();
    }
}

class SectionDiagram {
	public static final String EOF = System.lineSeparator();

	Deque<Integer> downhillDeque = new ArrayDeque<>();
	Deque<WaterHazardElement> waterHazardDeque = new ArrayDeque<>();
	int A = 0;
	int k = 0;
	StringBuilder sbL = new StringBuilder();
	
	public SectionDiagram analyze(String s) {
		int len = s.length();
		for(int i=0; i<len; i++) {
			switch(s.charAt(i)) {
			case '\\':
				downhillDeque.push(i);
				break;
			case '/':
				if(!downhillDeque.isEmpty()) {
					int start = downhillDeque.pop();
					WaterHazardElement wh = new WaterHazardElement(start,i);
					while(true) {
						if(!waterHazardDeque.isEmpty()){
							WaterHazardElement whPre = waterHazardDeque.getFirst();
							if(wh.include(whPre)) {
								if(!wh.merge(waterHazardDeque.removeFirst())){
									waterHazardDeque.addFirst(wh);
									break;
								}
							} else {
								waterHazardDeque.addFirst(wh);
								break;
							}
						}else{
							waterHazardDeque.addFirst(wh);
							break;
						}
					}
				}
				break;
			}
		}
		
		for(k=0; !waterHazardDeque.isEmpty(); k++){
			int c = waterHazardDeque.removeLast().getCapacity();
			A += c;
			sbL.append(" ").append(c);
		}
		return this;
	}
	
	public String toString() {
		StringBuilder sb = new StringBuilder();
		sb.append(A).append(EOF);
		sb.append(k).append(sbL).append(EOF);
		return sb.toString();
	}
	
}

class WaterHazardElement {
	int st = -1;
	int ed = -1;
	int childCapacity = 0;
	
	public WaterHazardElement(int st, int ed) {
		this.st = st;
		this.ed = ed;
	}
	
	public boolean merge(WaterHazardElement s) {
		childCapacity += s.getCapacity();
		return (s.st - this.st >= 3);
	}
	
	public int getCapacity() {
		return childCapacity + ed - st;
	}
	
	public boolean include(WaterHazardElement s) {
		return this.st < s.st && s.ed < this.ed;
	}
	
}
 
class SimpleInputUtil {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
 
    public String[] readStrArray(String delim) throws NumberFormatException, IOException{
        return br.readLine().split(delim);
    }
     
    public int readInt() throws NumberFormatException, IOException{
        return Integer.parseInt(br.readLine());
    }
     
    public int[] readIntArray(int[] a) throws NumberFormatException, IOException{
        int i=0;
        while(i<a.length) {
            for(String s: br.readLine().split(" ")){
                if(i<a.length) {
                    a[i++] = Integer.parseInt(s);
                }
            }
        }
        return a;
    }
 
     
}