Algorithms: Dynamic Programming Tutorials and Code Examples - Page 10

Dot Star Regular Expression Matching in C

This small matcher supports whole-sequence matching with a wildcard token and repetition of the preceding token..

c

int regex_match(const int *text, size_t text_length, const int *pattern, size_t pattern_length) {
    int alg_error = 0;
    int alg_result = INT_MIN;
    errno = 0;
    int *dp = NULL;
    if (text_length > 1000000 || (text_length && !text)) { errno = EINVAL; alg_result = INT_MIN; goto alg_cleanup; }
    if (pattern_length > 1000000 || (pattern_length && !pattern)) { errno = EINVAL; alg_result = INT_MIN; goto alg_cleanup; }
    int n = (int)text_length;
    if (alg_error) { errno = ERANGE; alg_result = INT_MIN; goto alg_cleanup; }
    int m = (int)pattern_length;
    if (alg_error) { errno = ERANGE; alg_result = INT_MIN; goto alg_cleanup; }
    if (!(((n >= 0) && (n <= 1000000)))) { errno = EINVAL; alg_result = INT_MIN; goto alg_cleanup; }

Nov 15, 2026 C

Algorithms: Dynamic Programming

Dot Star Regular Expression Matching in C++

This small matcher supports whole-sequence matching with a wildcard token and repetition of the preceding token..

cpp

int regex_match(const std::vector<int>& text, const std::vector<int>& pattern) {
    alg_require(text.size() <= 1000000);
    alg_require(pattern.size() <= 1000000);
    int n = (int)text.size();
    int m = (int)pattern.size();
    alg_require(((n >= 0) && (n <= 1000000)));
    alg_require(((m >= 0) && (m <= 1000000)));
    alg_require(((int)pattern.size() == m));
    alg_require(((int)text.size() == n));
    for (int alg_i = 0; alg_i < m; alg_i++) {
        alg_require((pattern[alg_i] >= alg_sub(0, 2)));
        alg_require(((pattern[alg_i] != alg_sub(0, 2)) || ((alg_i > 0) && (pattern[alg_sub(alg_i, 1)] != alg_sub(0, 2)))));

Nov 15, 2026 C++

Algorithms: Dynamic Programming

Dot Star Regular Expression Matching in C#

This small matcher supports whole-sequence matching with a wildcard token and repetition of the preceding token..

csharp

    static int regex_match(ReadOnlySpan<int> text, ReadOnlySpan<int> pattern) {
        checked {
            int n = text.Length;
            int m = pattern.Length;
            alg_require(((n >= 0) && (n <= 1000000)));
            alg_require(((m >= 0) && (m <= 1000000)));
            alg_require((pattern.Length == m));
            alg_require((text.Length == n));
            for (int alg_i = 0; alg_i < m; alg_i++) {
                alg_require((pattern[alg_i] >= (-2)));
                alg_require(((pattern[alg_i] != (-2)) || ((alg_i > 0) && (pattern[(alg_i - 1)] != (-2)))));
            }

Nov 15, 2026 csharp

Algorithms: Dynamic Programming

Dot Star Regular Expression Matching in PHP

This small matcher supports whole-sequence matching with a wildcard token and repetition of the preceding token..

php

function regex_match(array $text, array $pattern): int {
    alg_require(array_is_list($text));
    alg_require(array_is_list($pattern));
    $n = count($text);
    $m = count($pattern);
    alg_require((($n >= 0) && ($n <= 1000000)));
    alg_require((($m >= 0) && ($m <= 1000000)));
    alg_require((count($pattern) == $m));
    alg_require((count($text) == $n));
    for ($alg_i = 0; $alg_i < $m; $alg_i++) {
        alg_require(($pattern[$alg_i] >= alg_sub(0, 2)));
        alg_require((($pattern[$alg_i] != alg_sub(0, 2)) || (($alg_i > 0) && ($pattern[alg_sub($alg_i, 1)] != alg_sub(0, 2)))));

Nov 15, 2026 PHP

Algorithms: Dynamic Programming

Fast Doubling Fibonacci in Java

Fast doubling computes Fibonacci numbers using identities for doubling an index, reducing the number of recurrence steps logarithmically..

java

    static int fast_fibonacci(int n) {
        alg_require(((n >= 0) && (n <= 1000000)));
        alg_require(((n >= 0) && (n <= 45)));
        int a = 0;
        int b = 1;
        int c = 0;
        int d = 0;
        int bit = 1;
        while ((bit <= (n / 2))) {
            bit = Math.multiplyExact(bit, 2);
        }
        while ((bit > 0)) {

Nov 15, 2026 Java