In C language, pattern searching is the process of finding a specific sequence of characters (known as the pattern) within a larger string (known as the text). There are various algorithms that can be used to perform pattern searching, with different trade-offs in terms of performance and complexity.

The most basic algorithm for pattern searching is the brute-force algorithm, also known as the naive algorithm. It compares each character of the text with the corresponding character of the pattern, and if a mismatch is found, it starts over from the next character in the text.

Here is an example of the brute-force algorithm implemented in C:

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#include <stdio.h> int search(char* text, char* pattern) {    int n = strlen(text);    int m = strlen(pattern);    for (int i = 0; i <= n - m; i++) {        int j;        for (j = 0; j < m; j++) {            if (text[i + j] != pattern[j]) {                break;            }        }        if (j == m) {            return i;        }    }    return -1; } int main() {    char text[] = "Hello, world!";    char pattern[] = "world";    int index = search(text, pattern);    if (index == -1) {        printf("Pattern not found in text.\n");    } else {        printf("Pattern found at index %d.\n", index);    }    return 0; }

In this example, the function search() takes a text and a pattern as input and returns the starting index of the first occurrence of the pattern in the text. If the pattern is not found in the text, it returns -1.

However, the brute-