Given an unsorted array Arr of N positive and negative numbers. Your task is to create an array of alternate positive and negative numbers without changing the relative order of positive and negative numbers.

Example 1:

```Input:
N = 9
Arr[] = {9, 4, -2, -1, 5, 0, -5, -3, 2}
Output:
9 -2 4 -1 5 -5 0 -3 2
```

Example 2:

```Input:
N = 10
Arr[] = {-5, -2, 5, 2, 4, 7, 1, 8, 0, -8}
Output:
5 -5 2 -2 4 -8 7 1 8 0

```

method:

store the array elements positive and negative separately. Then combine them accoring to the condition.

c++ implementation:

```	void rearrange(int arr[], int n)
{
int b[n];int c[n];int x=0; int y=0;
for(int i=0;i<n;i++)
{
if(arr[i]<0)
{
b[x]=arr[i];
x++;
}
else
{
c[y]=arr[i];
y++;
}
}

int u=0;int v=0;int f=0;int i=0;
while(u<x && v<y)
{
if(f==1)
{
arr[i]=b[u];
u++;
}
else
{
arr[i]=c[v];
v++;
}
f=!f;
i++;
}

while(u<x)
{
arr[i]=b[u];
u++;
i++;
}

while(v<y)
{
arr[i]=c[v];
v++;
i++;
}
}```

above one is using arrays

(or )  //both are same

below one is using vectors

```	   void rearrange(int arr[], int n)
{
vector<int> n, p;
for (int i = 0; i < n; i++) {

if (arr[i] < 0)
n.push_back(arr[i]);
else
p.push_back(arr[i]);
}

int i = 0, j = 0, k = 0;
while (i < n.size() && j < p.size()) {
arr[k++] = p[j++];
arr[k++] = n[i++];
}
while (j < p.size()) { arr[k++] = p[j++]; }

while (i < n.size()) { arr[k++] = n[i++]; }
}```
Time Complexity: O(n)
space Complexity: O(n)

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