I am a grade 12 student from Mumbai. I am planning to appear for the Zonal Computing Olympiad this Saturday which is for school students. I am facing a problem regarding a particular question from ZCO 2012. There is a test page where users can submit the solution and receive the results. I have submitted my solution however it says that the answer is wrong. It says that the program compiled successfully without any errors or warnings. The problem gives the right answer on my machine for the given example. I provide the question and my code below:

Question:

Zonal Computing Olympiad 2012, 26 Nov

2011 10:00 am-1:00 pm IST Problem 1 :

Matched BracketsA sequence of opening and closing

brackets is well-bracketed if we can

pair up each opening bracket with a

matching closing bracket in the usual

sense. For instance, the sequences (),

(()) and ()(()) are well-bracketed,

while (, ()), (()(), and )( are not

well-bracketed.The nesting depth of a well-bracketed

sequence tells us the maximum number

of levels of inner matched brackets

enclosed within outer matched

brackets. For instance, the nesting

depth of () and ()()() is 1, the

nesting depth of (()) and ()(()) is 2,

the nesting depth of ((())) is 3, and

so on.Given a well-bracketed sequence, we

are interested in computing the

following:`The nesting depth, and the first position where it occurs-this will be`

the position of the first opening

bracket at this nesting depth, where

the positions are numbered starting

with 1.`The maximum number of symbols between any pair of matched brackets,`

including both the outer brackets, and

the first position where this

occurs-that is, the position of the

first opening bracket of this segment.For instance, the nesting depth of

()(())()(()())(()()) is 2 and the

first position where this occurs is 4.

The opening bracket at position 10 is

also at nesting depth 2 but we have to

report the first position where this

occurs, which is 4.In this sequence, the maximum number

of symbols between a pair of matched

bracket is 6, starting at position 9.

There is another such sequence of

length 6 starting at position 15, but

this is not the first such position.

Input formatThe input consists of two lines. The

first line is a single integer N, the

length of the bracket sequence.

Positions in the sequence are numbered

1,2,…,N. The second line is a sequence

of N space-separated integers that

encode the bracket expression as

follows: 1 denotes an opening bracket

( and 2 denotes a closing bracket ).

Nothing other than 1 or 2 appears in

the second line of input and the

corresponding expression is guaranteed

to be well-bracketed. Output formatYour program should print 4

space-separated integers in a line,

denoting the four quantities asked for

in the following order: nesting depth,

first position that achieves the

nesting depth, length of the maximum

sequence between matching brackets and

the first position where such a

maximum length sequence occurs.

TestdataYou may assume that 2 ? N ? 105. In

30% of the test cases, 2 ? N ? 103.

Sample Input20 1 2 1 1 2 2 1 2 1 1 2 1 2 2 1 1 2 1

2 2Sample Output

2 4 6 9

Time and memory limits

The time limit for this task is 1

second. The memory limit is 32MB.

My submitted solution is:

```
#include "iostream"
#include<stdio.h>
using namespace std;
int main()
{
unsigned int i,n,o,c,dep,pos_d,pos_m,last_pos,max;
char* arr,*rn;
cin>>n;
fflush(stdin);
arr = new char [2*n];
rn = fgets(arr, (2*n), stdin);
c=o=dep=pos_d=pos_m=last_pos=max=0;
for(i=0;arr[i];i++)
{
if(arr[i]==' ')
continue;
else if(arr[i]=='1')
{
o++;
if(c>0)
c--;
else
{
dep++;
pos_d = (i/2)+1;
}
}
else if(arr[i]=='2')
{
c++;
if(o>0)
o--;
if(o==0)
{
if(((i-last_pos+2)/2)>max)
{
max=(i-last_pos+2)/2;
pos_m = 1+(last_pos+1)/2;
}
last_pos = i+1;
}
}
}
cout<<dep<<" "<<pos_d<<" "<<max<<" "<<pos_m;
return 0;
}
```

Kindly help me find the problem as I don’t see any error and I seem to be getting the right answer for the given example.

Some useful links:

ZCO 2012 Question paper: http://www.iarcs.org.in/inoi/2012/zco2012/zco2012-1a.php

Test server site: http://www.iarcs.org.in/zco2013/index.php