Permutations (Editorial)

In this problem you must generate all permutations of numbers from $1$ to $n$. This can be done, for example, using the next_permutation function.

Algorithm implementation

Use the array $m$ to generate the permutations.

int m[10];

Read the input value of $n$.

scanf("%d",&n);

Initialize the array $m$ with the initial permutation 1~2~3~...~n, starting from the first index.

for (i = 1; i <= n; i++)
  m[i] = i;

Using the next_permutation function, generate all permutations — from the lexicographically smallest to the lexicographically largest.

do
{

Print each generated permutation on a separate line.

  for (i = 1; i <= n; i++) 
    printf("%d ",m[i]);
  printf("\n");
} while (next_permutation(m + 1, m + n + 1));

Algorithm implementation — vector

Use the vector $v$ to generate the permutations.

vector<int> v;

Read the input value of $n$.

scanf("%d", &n);

Initialize the array $v$ with the initial permutation 1~2~3~...~n, starting from the zero index.

v.resize(n);
for (i = 0; i < n; i++) 
  v[i] = i + 1;

Using the next_permutation function, generate all permutations — from the lexicographically smallest to the lexicographically largest.

do
{

Print each generated permutation on a separate line.

  for (i = 0; i < n; i++)
    printf("%d ", v[i]);
  printf("\n");
} while (next_permutation(v.begin(), v.end()));