Display records sorted by name from file

Logic. The records (name and roll) are stored in a text file records.txt, one record per line. The program reads them into an array of structures with fscanf(), sorts the array in ascending order of name with strcmp() (bubble sort, swapping whole structures) and displays them.

#include <stdio.h>
#include <string.h>
#define MAX 100

struct rec {
    char name[30];
    int roll;
};

int main(void)
{
    struct rec r[MAX], t;
    int n = 0;
    FILE *fp = fopen("records.txt", "r");

    if (fp == NULL) {
        printf("Cannot open records.txt\n");
        return 1;
    }
    while (n < MAX && fscanf(fp, "%29s %d", r[n].name, &r[n].roll) == 2)
        n++;
    fclose(fp);

    for (int i = 0; i < n - 1; i++)
        for (int j = 0; j < n - 1 - i; j++)
            if (strcmp(r[j].name, r[j + 1].name) > 0) {
                t = r[j]; r[j] = r[j + 1]; r[j + 1] = t;
            }

    printf("%-10s %s\n", "Name", "Roll");
    for (int i = 0; i < n; i++)
        printf("%-10s %d\n", r[i].name, r[i].roll);
    return 0;
}

Output (records.txt had the lines: Ram 1, Sita 2, Bibek 3, Hari 4, Anil 5)

Name       Roll
Anil       5
Bibek      3
Hari       4
Ram        1
Sita       2