Algorithms: Searching

    static int linear_search(ReadOnlySpan<int> a, int target) {
        checked {
            int n = a.Length;
            alg_require(((n >= 0) && (n <= 1000000)));
            alg_require((a.Length == n));
            int i = 0;
            while ((i < n)) {
                if ((a[i] == target)) {
                    return i;
                }
                i = (i + 1);
            }