Computer Network practical practise problems

bit_stuffing.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX 100

int main(void) {
	char data[MAX], output_data[MAX+MAX];
	printf("Enter the data: ");
	scanf("%s", data);

	int len = strlen(data);
	int consec = 0;
	int j = 0;

	for(int i = 0; i < len; i++) {
		if (consec == 5 && data[i] == '1') {
			output_data[j++] = '0';
			output_data[j++] = '1';
			consec = 0;
		}
		
		else if (data[i] == '0') {
			output_data[j++] = '0';
			consec = 0;
		}

		else if (data[i] == '1') {
			output_data[j++] = '1';
			consec += 1;
		}
	}

	printf("Output data is: %s\n", output_data);

	consec = 0, j = 0;
	char decode_data[MAX+MAX];

	for(int i = 0; i < strlen(output_data); i++) {
		if (consec == 5 && output_data[i] == '0') {
			decode_data[j++] = '1';
			consec = 0;
		}

		else if (output_data[i] == '0') {
			decode_data[j++] = '0';
			consec = 0;
		}

		else if (output_data[i] == '1') {
			decode_data[j++] = '1';
			consec += 1;
		}
	}

	printf("Decoded data is: %s\n", decode_data);

	return 0;
}

character_count.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX 100

int main(void) {
	char data[MAX][MAX];
	char data_out[MAX][MAX];
	int len_frames = 0;
	printf("Enter the number of frames: ");
	scanf("%d", &len_frames);

	for(int i = 0; i < len_frames; i++) {
		printf("Enter frame %d: ", i);
		scanf("%s", data[i]);

		for(int j = 0; j < strlen(data[i]) + 1; j++) {
			if(j == 0)
				data_out[i][j] = strlen(data[i]) + '0';
			else
				data_out[i][j] = data[i][j-1];
		}

		printf("String is: %s\n", data_out[i]);
	}

	return 0;
}

checksum.c

#include <stdio.h>
#include <stdlib.h>
#define MAX 8

int main(void) {
	int len = 0;
	printf("Enter the no. of frames of %d size: ", MAX);
	scanf("%d", &len);
	int m_len = len;

	char frames[len][MAX];

	for(int i = 0; i < len; i++) {
		printf("Enter frame %d: ", i);
		scanf("%s", frames[i]);
	}

	char inter[MAX];
	for(int i = 0; i < MAX; i++) {
		inter[i] = frames[0][i];
	}

	for(int i = 1; i < m_len; i++) {
		printf("%s\n", inter);	
		for(int j = 0; j < MAX; j++) {
			int frame_int = frames[i][j] - '0';
			int inter_int = inter[j] - '0';

			int new_inter = frame_int ^ inter_int;
			inter[j] = new_inter + '0';
		}
		printf("%s\n", inter);
	}

	for(int i = 0; i < MAX; i++) {
		if (inter[i] == '0')
			inter[i] = '1';
		else
			inter[i] = '0';
	}
	printf("%s\n", inter);

	return 0;
}

crc.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX 100

int main(void) {
	char gen[MAX], data[MAX];

	printf("Enter the generator: ");
	scanf("%s", gen);

	printf("Enter data: ");
	scanf("%s", data);

	char mod_data[strlen(data)+strlen(gen)-1];

	for(int i = 0; i < strlen(gen)+strlen(data)-1; i++) {
		if (i < strlen(data))
			mod_data[i] = data[i];
		else
			mod_data[i] = '0';
	}

	char prev[strlen(gen)];
	for(int i = 0; i < strlen(gen); i++) {
		prev[i] = mod_data[i];
	}

	printf("SENDER\n");

	for(int i = 0; i < strlen(data); i++) {
		for(int j = 0; j < strlen(gen); j++) {
			int curr_j = gen[j] - '0';
			int curr_prev = prev[j] - '0';
			int curr_res = curr_j ^ curr_prev;
			prev[j] = curr_res + '0';
		}

		for(int j = 0; j < strlen(gen); j++) {
			if (j < strlen(gen) - 1)
				prev[j] = prev[j+1];
			else {
				prev[j] = mod_data[i + strlen(gen)];
			}
		}
		printf("%s\n", prev);
	}

	printf("RECEIVER\n");

	int x = 0;
	for(int i = 0; i < strlen(data) + strlen(prev); i++) {
		if(i < strlen(data))
			mod_data[i] = data[i];
		else {
			mod_data[i] = prev[x];
			x+=1;
		}
	}
	for(int i = 0; i < strlen(gen); i++) {
		prev[i] = mod_data[i];
	}

	for(int i = 0; i < strlen(data)+1; i++) {
		printf("%s\n", prev);
		for(int j = 0; j < strlen(gen); j++) {
			int curr_j = gen[j] - '0';
			int curr_prev = prev[j] - '0';
			int curr_res = curr_j ^ curr_prev;
			prev[j] = curr_res + '0';
		}

		for(int j = 0; j < strlen(gen); j++) {
			if (j < strlen(gen) - 1)
				prev[j] = prev[j+1];
			else {
				prev[j] = mod_data[i + strlen(gen)];
			}
		}
	}

	return 0;
}