C + + write generation of _c random number code language

C + + Write generates a random number code that does not duplicate

vector<int> getrandom (int total)
{
  srand (int) time (NULL));
  std::vector<int> input = *new std::vector<int> ();
  for (int i = 0; i < total; i++) {
    input.push_back (i);
  }
  vector<int> output = *new vector<int> ();
   
  int end = Total;
  for (int i = 0; i < total; i++) {
    Vector<int>::iterator iter = Input.begin ();
    int num = random ()%end;
    iter = Iter+num;
    Output.push_back (*iter);
    Input.erase (ITER);
    end--;
  }
   
  return output;
}

One more example:

void permutation (int n, int *z_array)
{
  int i, j, K, Z;
  int buffer[n];

  /* Initialize array *
  /for (i=0; i<n; i++)
    buffer[i]=0;

  /* Prepare to generate random numbers, seeded at current time/
  Srand ((unsigned) ((long *) 0));

  /* Obtain the random data for the i<n; (
  i=0; i++) {//
    * obtain 0~ (n-i) (*
    z = rand ()% (n-i);
    j=0; k=0;
    while (j<=z) {
      if (buffer[j+k]==0) j + +;
      else k++;
    }
    Buffer[j+k-1]=1;
    z_array[i]=j+k-1;
  }
  return;
}

Method Three: to a complex point

#include <stdio.h>
#include <time.h>
#include "iostream"
#include <math.h>
# Define N
using namespace std;

Print array
void display (int *a)
{for
    (int i =0;i<n;i++)
    {
      cout<< "" <<a[i] << "";
    }

}

int main (void)
{

  int b[n],a[n];
  for (int i =0;i<n;i++)
  {
    b[i] = i+1;
  }
  Random (a);
  Srand ((unsigned) time (NULL));
  int maxindex = N;
  for (i= 0;i<n;i++)
  {

  // 
    int index = (int) rand ()%maxindex;//a random index of 0-52
    a[i] = b[index];
   //random numbers to the a[i],i from 0 to N-1
    b[index] = b[maxindex-1];
    maxindex--;

  }
    Display (a);
  return 0;

All of the above 3 methods can be achieved to generate a random number of duplicates, the specific efficiency, the small partners themselves test it.