crc.cpp

/*
 * CRC
 * Created on: 01-Oct-2014
 * Author: Gourav Siddhad
 */

#include <cstring>
#include <iostream>
#define MAX 20
using namespace std;

char myxor(char x, char y) {
    if (x == y)
        return '0';
    else
        return '1';
}

int main() {
    char msg[MAX], gen[MAX], temp[MAX], trans[MAX];
    unsigned int m, g, k;

    cout << " Enter The Message : ";
    cin >> msg;  // Input The Message To Be Transmitted
    strcpy(temp, msg);
    m = strlen(msg);

    cout << " Enter The Generator (Must Start With 1) : ";
    cin >> gen;  // Input The Generator Polynomial
    g = strlen(gen);

    if (strlen(msg) == 0 || strlen(gen) == 0) {
        cout << " Can't Generate Message To Be Transmitted .. ";
        return 0;
    }

    for (k = 0; k < g - 1; ++k)  // Appending Zero's At The End Of Message
        temp[m++] = '0';
    temp[m] = '\0';

    strcpy(trans, temp);

    unsigned int i = 0;
    while (i <= (m - g))  // Starting Divisio0n
    {
        if (temp[i] == '1') {
            for (k = 0; k < g; k++)
                temp[i + k] = myxor(temp[i + k], gen[k]);
        }
        if (temp[i] == '1')
            continue;
        else
            ++i;
    }

    for (k = 0; k < g; k++)  // Conctatinating Last Bits To Transmitting Message
        trans[m - k] = temp[m - k];

    cout << "\n The Message To Be Transmitted Is : ";
    cout << trans;

    return 0;
}

dijkstra.cpp

#include<iostream>
#include<climits>
using namespace std;

int miniDist(int distance[], bool Tset[])
{
    int minimum=INT_MAX,ind;

    for(int k=0;k<6;k++)
    {
        if(Tset[k]==false && distance[k]<=minimum)
        {
            minimum=distance[k];
            ind=k;
        }
    }
    return ind;
}

void DijkstraAlgo(int graph[6][6],int src)
{
    int distance[6];
    bool Tset[6];

    for(int k = 0; k<6; k++)
    {
        distance[k] = INT_MAX;
        Tset[k] = false;
    }

    distance[src] = 0;

    for(int k = 0; k<6; k++)
    {
        int m=miniDist(distance,Tset);
        Tset[m]=true;
        for(int k = 0; k<6; k++)
        {
            if(!Tset[k] && graph[m][k] && distance[m]!=INT_MAX && distance[m]+graph[m][k]<distance[k])
                distance[k]=distance[m]+graph[m][k];
        }
    }
    cout<<"Vertex\t\tDistance from source vertex"<<endl;
    for(int k = 0; k<6; k++)
    {
        char str=65+k;
        cout<<str<<"\t\t\t"<<distance[k]<<endl;
    }
}

int main()
{
    int graph[6][6]={
        {0, 1, 2, 0, 0, 0},
        {1, 0, 0, 5, 1, 0},
        {2, 0, 0, 2, 3, 0},
        {0, 5, 2, 0, 2, 2},
        {0, 1, 3, 2, 0, 1},
        {0, 0, 0, 2, 1, 0}};
    DijkstraAlgo(graph,0);
    return 0;
}

selective_repeat.cpp

/*
 * 	Selective Repeat Slide
 *  Created on: 01-Nov-2014
 *      Author: Gourav Siddhad
 */

#include <time.h>

#include <cstdlib>
#include <iostream>
using namespace std;

static int done = 0;
void sender(int, int);
int receiver(int[], bool[], int);

bool success(int success = 80) {
    return rand() % 100 < success;
}

void sender(const int f, const int w) {
    int temp = 0;
    int frames[w + 1], win = 0;
    bool ack[w + 1], ackno[f + 1];

    for (int j = 0; j <= f; j++) ackno[j] = 0;

    for (int i = 0; i < f;) {
        win = 0, temp = i;
        for (int j = 0; j < f; j++) {
            if (win == w) break;
            if (ackno[j] == 0) {
                ack[win] = 0;
                frames[win] = j;
                win++;
            }
        }

        cout << "\n Frames Sent : " << win << " | ";
        for (int j = 0; j < win; j++)
            if (ack[j] == 0)
                cout << frames[j] + 1 << " ";
            else {
                if ((frames[j] + 1) % 100 > 10)
                    cout << " ";
                cout << "  ";
            }

        i = receiver(frames, ack, win);
        for (int j = 0; j < win; j++) {
            ackno[frames[j]] = ack[j];
        }

        if (i == temp)
            cout << "\n Time Out... Resending... ";
    }
}

int receiver(int frames[], bool ack[], int win) {
    for (int i = 0; i < win; i++) {
        ack[i] = success();
    }

    cout << "\n Frames Received ";
    if (win % 100 > 9)
        cout << " ";
    cout << "| ";

    for (int i = 0; i < win; i++)
        if (ack[i] == 1) {
            cout << frames[i] + 1 << " ";
            done++;
        } else {
            if ((frames[i] + 1) % 100 > 9)
                cout << " ";
            cout << "  ";
        }

    cout << endl;
    return done;
}

int main() {
    srand(time(NULL));
    int f, w;
    cout << " Enter The Number Of Frames : ";
    cin >> f;
    cout << " Enter Window Size : ";
    cin >> w;
    sender(f, w);
    return 0;
}

sliding_window.cpp

// Go Back N
// Stop and Wait if window size is 1


#include <math.h>
#include <time.h>

#include <cstdlib>
#include <iostream>
using namespace std;

static int r = 0;
void sender(int);
bool receiver(int, int);

bool success(int success = 80) {
    return rand() % 100 < success;
}

void sender(int n, int w = 1) {
    int rec = 0, i = 1, init = 0;
    int bit, seq = (pow(2, w - 1) + 1);
    while (i <= n) {
        init = i;

        cout << "\n Frames Sent : " << w << " | ";
        for (int j = 0; j < w && j <= n - init; j++)
            cout << i + j << " ";

        for (int j = 0; j < w && j <= n - init; j++) {
            bit = (i - 1) % seq;
            cout << "\n Frame " << i << " | ";
            rec = receiver(bit, seq);
            if (rec) {
                cout << "Received";
                i += 1;
            } else {
                cout << "Timeout ";
                break;
            }
        }

        cout << "\n Frames Received | ";
        while (init < i) {
            cout << init << " ";
            init += 1;
        }
        cout << endl;
    }
}

bool receiver(int fbit, int seq) {
    if (success()) {
        if (r == fbit) {
            r = (r + 1) % seq;
        } else
            cout << "Duplicate ";
        return success(90);
    } else {
        cout << "Damaged ";
        return false;
    }
}

int main() {
    srand(time(NULL));
    int n = 0, w = 1;
    cout << " Enter The Number Of Frames : ";
    cin >> n;
    cout << " Enter The window size : ";
    cin >> w;
    sender(n, w);
    return 0;
}