Inversiot

input/code.cpp: In function 'void invert(std::vector<int>&, int, int, int, int)':
input/code.cpp:19:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if (i2 < v.size() - 1 - r)
         ^
input/code.cpp: In function 'int main()':
input/code.cpp:39:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < v.size(); i++)
                    ^
input/code.cpp:41:17: warning: ignoring return value of 'int system(const char*)', declared with attribute warn_unused_result [-Wunused-result]
  system("pause");
                 ^

#include <iostream>
#include <vector>

using namespace std;

void flip(vector<int> &v, int i1, int i2)
{
	int temp = v[i1];
	v[i1] = v[i2];
	v[i2] = temp;
}

void invert(vector<int> &v, int k, int r = 0, int i1 = 0, int i2 = 1)
{
	if (k <= 0) return;

	flip(v, i1, i2);
	
	if (i2 < v.size() - 1 - r)
		invert(v, k - 1, r, i1 + 1, i2 + 1);
	else
		invert(v, k - 1, r + 1, 0, 1);
}

int main()
{
	int n;
	cin >> n;

	int k;
	cin >> k;

	vector<int> v;
	for (int i = 1; i <= n; i++)
		v.push_back(i);

	invert(v, k);

	for (int i = 0; i < v.size(); i++)
		cout << v[i] << " ";
	system("pause");
	return 0;
}

Test 1

Group: 1

Verdict: ACCEPTED

sh: 1: pause: not found

Test 2

Group: 1

Verdict: ACCEPTED

sh: 1: pause: not found

Test 3

Group: 1

Verdict: ACCEPTED

sh: 1: pause: not found

Test 4

Group: 1

Verdict: ACCEPTED

sh: 1: pause: not found

Test 5

Group: 1

Verdict: ACCEPTED

sh: 1: pause: not found

Test 6

Group: 2

Verdict: ACCEPTED

sh: 1: pause: not found

Test 7

Group: 2

Verdict: ACCEPTED

sh: 1: pause: not found

Test 8

Group: 2

Verdict: ACCEPTED

sh: 1: pause: not found

Test 9

Group: 2

Verdict: ACCEPTED

sh: 1: pause: not found

Test 10

Group: 2

Verdict: ACCEPTED

sh: 1: pause: not found

Test 11

Group: 3

Verdict: ACCEPTED

sh: 1: pause: not found

Test 12

Group: 3

Verdict: ACCEPTED

sh: 1: pause: not found

Test 13

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 14

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 15

Group: 3

Verdict: TIME LIMIT EXCEEDED