Given two character strings s1 and s2. Using C and pthread to write a parallel program to find out the number of substrings, in string s1, that are exactly the same as string s2. The strings are ended with ‘\0’. For example, suppose number_substring(s1, s2) implements the function, then number_substring(“abcdab”, “ab”) = 2, number_substring(“aaa”, “a”) = 3, number_substring(“abac”, “bc”) = 0. Suppose the size of s1 and s2 are n1 and n2, respectively, and p threads are used, we assume that n1 mod p = 0, and n2 < n1/p. Strings s1 and s2 are stored in a file named “strings.txt”. String s1 is evenly partitioned among p threads to concurrently search for matching with string s2. After a thread finishes its work and obtains the number of local matchings, this local number is added into a global variable showing the total number of matched substrings in string s1. Finally this total number is printed out. The format of the strings.txt is like this (the first string is s1 and the second one is s2):
abcassghbca
bca
In the program, use #define to specify number of threads to be created. For example:
#define NUM_THREADS 5