swarajd

swarajd@swarajd-travel:~/prog/systems/3ep/29_locked_data_structures$ ./concurrent_counter 
it took: 0.261783 seconds to run 1 threads
it took: 1.349552 seconds to run 2 threads
it took: 2.434678 seconds to run 3 threads
it took: 4.624687 seconds to run 4 threads
it took: 6.601393 seconds to run 5 threads
swarajd@swarajd-travel:~/prog/systems/3ep/29_locked_data_structures$ ./better_concurrent_counter 
it took: 0.300315 seconds to run 1 threads
it took: 1.788734 seconds to run 2 threads
it took: 3.112465 seconds to run 3 threads

swarajd

#include <stdio.h>

#include "mythreads.h"

pthread_mutex_t m1 = PTHREAD_MUTEX_INITIALIZER;
pthread_mutex_t m2 = PTHREAD_MUTEX_INITIALIZER;

void* worker(void* arg) {
    if ((long long) arg == 0) {
	Pthread_mutex_lock(&m1);

swarajd

#define _GNU_SOURCE

#include <sched.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <string.h>
#include <stdio.h>
#include <sys/time.h>

swarajd

#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define READ_END 0
#define WRITE_END 1

swarajd

class Solution {
    public int reverse(int x) {
        int reversed = 0;
        while (x != 0) {
            int rem = x % 10;
            reversed += rem;
            int prevReverse = reversed;
            boolean xIsBig = x >= 10 || x <= -10;
            if (xIsBig) {
                reversed *= 10;

swarajd

class Solution {
    public int lengthOfLongestSubstring(String s) {
        
        HashSet<Character> seenSoFar = new HashSet<Character>();
        
        int curLength = 0;
        int longestSoFar = 0;
        int start = 0;
        int end = 0;
        

swarajd

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/wait.h>

int main(int argc, char** argv) {

    // print the args
    for (int i = 0; i < argc; ++i) {
        printf("%s\n", argv[i]);

swarajd

const gcd = (a, b) => {
    if (!b) {
        return a;
    }

    return gcd(b, a % b);
}

swarajd

const hill = (text, matrix) => {

    if (text.length % matrix.length != 0) {
        throw "please provide a plaintext that can be cleanly divided into " + matrix.length + " parts"
    }

    const chunks = [];
    for (let i = 0; i < text.length; i += matrix.length) {
        chunks.push(text.substring(i, i + matrix.length));
    }

swarajd

const getRandomInt = (min, max) => {
    return Math.floor(Math.random() * (max - min + 1)) + min;
}

const dValues = (() => {
    const result = new Array(27);
    result[0] = 1;
    result[1] = 0;
    for (let i = 2; i < letters.length; i++) {
        result[i] = (i - 1) * (result[i - 1] + result[i - 2]);