Balancing out the matrix with 0 and 1 in C programming

I am generating n x n (0,1) matrix. However I have no idea how to balance out 0 and 1 in the matrix. Each entry inside the matrix is either 0 or 1 such that every row have to contain exactly (n/2) 1's and (n/2) 0's. what code would you add to mine? I am in desperate help please.

so if I put the size 4 for matrix, initial 4 by 4 should look like this:

0011
0011
0101
0110

or any random location as long as it has (50:50) of (0,1) in each row

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include<stdbool.h>
#define R 80
#define C 80


void initialization(int n, int a[R][C])
{
    
    int i,j;
    //int row_flag = 0;
    
    for (i = 0; i<n;i++)    {
        for(j=0; j<n;j++)   {
                a[i][j] = rand()%2;
                printf("%d", a[i][j]);
            }
            printf("\n");
        }
}
            

int main()
{
    srand(time(NULL));
    int n=0;
    int a[R][C]={0, }; 
    printf("Enter the size of matrix, a positive even integer: ");
    scanf("%d",&n);
    if (n%2 ==0)  {
        initialization(n,a);
    }
    else    {
        return 0;
    }

    return 0;
}