Given an input string and a substring. Find the frequency of occurrences of a substring in the given string using pthreads. Examples:
Input: string = "man"
substring = "dhimanman"
Output: 2
Input: string = "banana"
substring = "nn"
Output: 0
Note: It is advised to execute the program in Linux based system. Compile in linux using following code:
g++ -pthread program_name.cpp
Program:
CPP
// C++ program to find the frequency // of occurrences of a substring // in the given string using pthread #include <iostream> #include <pthread.h> #include <stdlib.h> #include <sys/types.h> #include <time.h> #include <unistd.h> #define max 4 using namespace std; int count[max] = { 0 }; string str, sub; void* str_seq_count(void* args) { int value = *(int*)args; int i, j, k, l1, l2, flag; // calculating length of string 1 l1 = str.length(); // calculating length of substring l2 = sub.length(); for (i = 0 + value; i < l1; i = i + max) { flag = 0; k = i; for (j = 0; j < l2; j++) { // flag=0; if (sub[j] == str[k]) k++; else { flag = 1; break; } } if (flag == 0) count[value] += 1; } } // Driver code int main() { int sum = 0; int x[max]; for (int a = 0; a < max; a++) x[a] = a; str = "prrrogramisprrrogramming"; sub = "rr"; cout << "Enter the main string: " << str << endl; cout << "Enter the sequence to search: " << sub << endl; int i, l1; pthread_t tid[max]; for (i = 0; i < max; i++) { pthread_create(&tid[i], NULL, str_seq_count, (void*)&x[i]); } for (i = 0; i < max; i++) pthread_join(tid[i], NULL); for (i = 0; i < max; i++) sum = sum + count[i]; cout << "Frequency of substring: " << sum; return 0; } |
Java
// Java program for the above approachimport java.util.Arrays;public class Main { static final int max = 4; static int[] count = new int[max]; static String str, sub; public static void main(String[] args) { int sum = 0; final int[] x = new int[max]; for (int a = 0; a < max; a++) x[a] = a; str = "prrrogramisprrrogramming"; sub = "rr"; System.out.println("Enter the main string: " + str); System.out.println("Enter the sequence to search: " + sub); Thread[] tid = new Thread[max]; for (int i = 0; i < max; i++) { final int value = i; tid[i] = new Thread(() -> str_seq_count(x[value])); tid[i].start(); } for (int i = 0; i < max; i++) { try { tid[i].join(); } catch (InterruptedException e) { e.printStackTrace(); } } for (int i = 0; i < max; i++) sum = sum + count[i]; System.out.println("Frequency of substring: " + sum); } static void str_seq_count(int value) { int i, j, k, l1, l2, flag; // calculating length of string 1 l1 = str.length(); // calculating length of substring l2 = sub.length(); for (i = 0 + value; i < l1; i = i + max) { flag = 0; k = i; for (j = 0; j < l2; j++) { // flag=0; if (sub.charAt(j) == str.charAt(k)) k++; else { flag = 1; break; } } if (flag == 0) count[value] += 1; } }}// This code is contributed by adityashatmfh |
Python3
# Python program for the above approachimport threadingcount = [0] * 4str = "prrrogramisprrrogramming"sub = "rr"def str_seq_count(value): global count l1 = len(str) l2 = len(sub) for i in range(value, l1, 4): flag = 0 k = i for j in range(l2): if sub[j] == str[k]: k += 1 else: flag = 1 break if flag == 0: count[value] += 1if __name__ == '__main__': total_count = 0 x = [i for i in range(4)] print("Enter the main string: ", str) print("Enter the sequence to search: ", sub) threads = [] for i in range(4): t = threading.Thread(target=str_seq_count, args=(x[i],)) threads.append(t) t.start() for t in threads: t.join() total_count = sum(count) print("Frequency of substring: ", total_count)# This code is contributed by codebraxnzt |
C#
// C# program for the above approachusing System;using System.Threading;public class MainClass{ static readonly int max = 4; static int[] count = new int[max]; static string str, sub; public static void Main(string[] args) { int sum = 0; int[] x = new int[max]; for (int a = 0; a < max; a++) x[a] = a; str = "prrrogramisprrrogramming"; sub = "rr"; Console.WriteLine("Enter the main string: " + str); Console.WriteLine("Enter the sequence to search: " + sub); Thread[] tid = new Thread[max]; for (int i = 0; i < max; i++) { int value = i; tid[i] = new Thread(() => str_seq_count(x[value])); tid[i].Start(); } for (int i = 0; i < max; i++) { try { tid[i].Join(); } catch (ThreadInterruptedException e) { Console.WriteLine(e.StackTrace); } } for (int i = 0; i < max; i++) sum = sum + count[i]; Console.WriteLine("Frequency of substring: " + sum); } static void str_seq_count(int value) { int i, j, k, l1, l2, flag; // calculating length of string 1 l1 = str.Length; // calculating length of substring l2 = sub.Length; for (i = 0 + value; i < l1; i = i + max) { flag = 0; k = i; for (j = 0; j < l2; j++) { // flag=0; if (sub[j] == str[k]) k++; else { flag = 1; break; } } if (flag == 0) count[value] += 1; } }}// This code is contributed by Prince Kumar |
Javascript
// JavaScript program to find the frequency // of occurrences of a substring // in the given string using pthreadlet count = [0, 0, 0, 0];let str = "prrrogramisprrrogramming";let sub = "rr";function strSeqCount(value) { let l1 = str.length; let l2 = sub.length; for (let i = value; i < l1; i += 4) { let flag = 0; let k = i; for (let j = 0; j < l2; j++) { if (sub[j] === str[k]) { k++; } else { flag = 1; break; } } if (flag === 0) { count[value]++; } }}function runThreads() { let x = [0, 1, 2, 3]; console.log("Enter the main string: ", str); console.log("Enter the sequence to search: ", sub); let threadIndex = 0; function runNextThread() { if (threadIndex < x.length) { strSeqCount(x[threadIndex]); threadIndex++; setTimeout(runNextThread, 0); // Non-blocking I/O using setTimeout } else { finishExecution(); } } runNextThread();}function finishExecution() { let total_count = count.reduce((sum, value) => sum + value, 0); console.log("Frequency of substring: ", total_count);}runThreads();// This code is contributed by Samim Hossain Mondal |
Output:
Enter the main string: prrrogramisprrrogramming
Enter the sequence to search: rr
Frequency of substring: 4
Related article: Frequency of a substring in a string
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