Task: Bin given limits

C: #include <stdio.h>
#include <stdlib.h>

size_t upper_bound(const int* array, size_t n, int value) {
    size_t start = 0;
    while (n > 0) {
        size_t step = n / 2;
        size_t index = start + step;
        if (value >= array[index]) {
            start = index + 1;
            n -= step + 1;
        } else {
            n = step;
        }
    }
    return start;
}

int* bins(const int* limits, size_t nlimits, const int* data, size_t ndata) {
    int* result = calloc(nlimits + 1, sizeof(int));
    if (result == NULL)
        return NULL;
    for (size_t i = 0; i < ndata; ++i)
        ++result[upper_bound(limits, nlimits, data[i])];
    return result;
}

void print_bins(const int* limits, size_t n, const int* bins) {
    if (n == 0)
        return;
    printf("           < %3d: %2d\n", limits[0], bins[0]);
    for (size_t i = 1; i < n; ++i)
        printf(">= %3d and < %3d: %2d\n", limits[i - 1], limits[i], bins[i]);
    printf(">= %3d          : %2d\n", limits[n - 1], bins[n]);
}

int main() {
    const int limits1[] = {23, 37, 43, 53, 67, 83};
    const int data1[] = {95, 21, 94, 12, 99, 4,  70, 75, 83, 93, 52, 80, 57,
                         5,  53, 86, 65, 17, 92, 83, 71, 61, 54, 58, 47, 16,
                         8,  9,  32, 84, 7,  87, 46, 19, 30, 37, 96, 6,  98,
                         40, 79, 97, 45, 64, 60, 29, 49, 36, 43, 55};

    printf("Example 1:\n");
    size_t n = sizeof(limits1) / sizeof(int);
    int* b = bins(limits1, n, data1, sizeof(data1) / sizeof(int));
    if (b == NULL) {
        fprintf(stderr, "Out of memory\n");
        return EXIT_FAILURE;
    }
    print_bins(limits1, n, b);
    free(b);

    const int limits2[] = {14, 18, 249, 312, 389, 392, 513, 591, 634, 720};
    const int data2[] = {
        445, 814, 519, 697, 700, 130, 255, 889, 481, 122, 932, 77,  323, 525,
        570, 219, 367, 523, 442, 933, 416, 589, 930, 373, 202, 253, 775, 47,
        731, 685, 293, 126, 133, 450, 545, 100, 741, 583, 763, 306, 655, 267,
        248, 477, 549, 238, 62,  678, 98,  534, 622, 907, 406, 714, 184, 391,
        913, 42,  560, 247, 346, 860, 56,  138, 546, 38,  985, 948, 58,  213,
        799, 319, 390, 634, 458, 945, 733, 507, 916, 123, 345, 110, 720, 917,
        313, 845, 426, 9,   457, 628, 410, 723, 354, 895, 881, 953, 677, 137,
        397, 97,  854, 740, 83,  216, 421, 94,  517, 479, 292, 963, 376, 981,
        480, 39,  257, 272, 157, 5,   316, 395, 787, 942, 456, 242, 759, 898,
        576, 67,  298, 425, 894, 435, 831, 241, 989, 614, 987, 770, 384, 692,
        698, 765, 331, 487, 251, 600, 879, 342, 982, 527, 736, 795, 585, 40,
        54,  901, 408, 359, 577, 237, 605, 847, 353, 968, 832, 205, 838, 427,
        876, 959, 686, 646, 835, 127, 621, 892, 443, 198, 988, 791, 466, 23,
        707, 467, 33,  670, 921, 180, 991, 396, 160, 436, 717, 918, 8,   374,
        101, 684, 727, 749};

    printf("\nExample 2:\n");
    n = sizeof(limits2) / sizeof(int);
    b = bins(limits2, n, data2, sizeof(data2) / sizeof(int));
    if (b == NULL) {
        fprintf(stderr, "Out of memory\n");
        return EXIT_FAILURE;
    }
    print_bins(limits2, n, b);
    free(b);

    return EXIT_SUCCESS;
}