How to shuffle the array elements..?

#include<iostream>
#include<stdlib.h>
#include<time.h>
using namespace std;
int main()
{
int size,i;

cout<<"Enter the size of array:";
cin>>size;

int a[20];
cout<<"\nEnter the elements:";

for(i=0;i<size;i++)
cin>>a[i];

srand(time(0));
int k,t;


for(i=0;i<size;i++)
{
k=rand()%size;
t=a[i];        //a[i]=a[i]*a[k];
a[i]=a[k];     //a[k]=a[i]/a[k];
a[k]=t;        //a[i]=a[i]/a[k];
}

cout<<"\nShuffeled array:";
for(i=0;i<size;i++)
cout<<a[i]<<"\t";
cout<<endl;
return 0;
}