# Use stable_partition algorithms: preserving relative order in each group : stable_partition « STL Algorithms Modifying sequence operations « C++ Tutorial

```#include <algorithm>
#include <vector>
#include <string>
#include <iostream>
#include <iterator>
using namespace std;

bool above40(int n) { return (n > 4); }

int main()
{
const int N = 7;
int array0[N] = {5, 3, 1, 7, 6, 4, 2};
int array1[N];

copy(&array0[0], &array0[N], &array1[0]);

ostream_iterator<int> out(cout, " ");

cout << "Original sequence:                 ";
copy(&array1[0], &array1[N], out); cout << endl;

// Partition array1, putting numbers greater than 4
// first, followed by those less than or equal to 4,
// preserving relative order in each group:
int* split = stable_partition(&array1[0], &array1[N], above40);

cout << "Result of stable partitioning:     ";
copy(&array1[0], split, out); cout << "| ";
copy(split, &array1[N], out); cout << endl;
return 0;
}
```
```Original sequence:                 5 3 1 7 6 4 2
Result of stable partitioning:     5 7 6 | 3 1 4 2```
 24.20.stable_partition 24.20.1. Use stable_partition algorithms: preserving relative order in each group 24.20.2. Use stable_partition and partition