analysing code

Hey guys

I am looking and a piece of code that is masking and finding duplicates and I am trying to figure out what one piece of code does. The piece I don't understand is rc=match<=same.
Does anyone know what this does exactly and why it is relevant. I have never seen an assignment like this.

Code:

#include <stdio.h>
#define SIZE 5
int changeKey(int oldKey[], int newKey[], int n, int same) {
    int i, j, rc, match;

    match = 0;
    for (i = 0; i < n; i++)
        for (j = 0; j < n; j++)
            if (oldKey[i] == newKey[j])
                match++;
     rc = match <= same; /*what exactly does this do*/
	 printf("RC IS %d\n",rc);
	 printf("MATCH IS %d\n",match);
	
    if (rc == 1)
        for (i = 0; i < n; i++)
            oldKey[i] = newKey[i];
			

    return rc;
}


void display(int key[], int n) {
    int i;

    for (i = 0; i < n; i++)
        printf("%d", key[i]);
    printf("\n");
}

int main(void) {
    int key[] =      {1,0,2,6,7}, rc;
    int attempt1[] = {2,7,4,5,9};
    int attempt2[] = {1,8,5,2,9};

    display(key, SIZE);
    rc = changeKey(key, attempt1, SIZE, 1);
    if (rc == 1)
        printf("Changed to: ");
    else
        printf("Remains as: ");
    display(key, SIZE);
    rc = changeKey(key, attempt2, SIZE, 2);
    if (rc == 1)
        printf("Changed to: ");
    else
        printf("Remains as: ");
    display(key, SIZE);
    rc = changeKey(key, attempt1, SIZE, 3);
    if (rc == 1)
        printf("Changed to: ");
    else
        printf("Remains as: ");
    display(key, SIZE);

    return 0;
}

rc = match <= same; /*what exactly does this do*/

The result of comparison(<=) either 0 or 1 is assigned to rc.

First look at the precedence of the operators involved:
<= is higher precedence than =
Then bracket accordingly:
rc = (match <= same)
So first match is compared to same using less-than-or-equal, resulting in a boolean value (1 or 0)
Then this boolean value is assigned to rc.