#include <stdio.h>
 
char *input_argv[] = { "prog.c", "12", "10", "17", "1", "22" };     // al posto di argv[]
int   input_argc   = sizeof (input_argv) / sizeof (input_argv[0]);  // al posto di argc
 
void visualizza (int lista[], int dimensione)
{
    int i;
 
    for (i = 0; i < dimensione; i++)
      {
        printf ("%i ", lista[i]);
      }
    printf ("\n");
}
 
void permuta (int lista[], int a, int z, int dimensione)
{
    int scambio;
    int k;
 
    // Se il segmento di array contiene almeno due elementi,
    // si procede.
 
    if ((z - a) >= 1)
      {
        // Inizia un ciclo di scambi tra l'ultimo elemento e
        // uno degli altri contenuti nel segmento di array.
 
        for (k = z; k >= a; k--)
          {
            // Scambia i valori.
 
            scambio = lista[k];
            lista[k] = lista[z];
            lista[z] = scambio;
 
            // Esegue una chiamata ricorsiva per permutare
            // un segmento più piccolo dell'array.
 
            permuta (lista, a, z - 1, dimensione);
 
            // Scambia i valori.
 
            scambio = lista[k];
            lista[k] = lista[z];
            lista[z] = scambio;
          }
      }
    else
      {
        // Visualizza l'array.
 
        visualizza (lista, dimensione);
      }
}
 
int
main (int argc, char *argv[])
{
    int lista[input_argc - 1];
    int i;
 
    // Considera gli argomenti come gli elementi
    // dell'array da permutare.
 
    for (i = 1; i < input_argc; i++)
      {
        sscanf (input_argv[i], "%i", &lista[i-1]);
      }
 
    // Esegue le permutazioni.
 
    permuta (lista, 0, input_argc - 2, input_argc - 1);
 
    return 0;
}
 

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