A5.c

#include <stdio.h>
#define SIZEX 19
#define SIZEY 22
#define SIZEZ 23

int maj(int, int, int);

int main(){
        int x[SIZEX] = {1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1};
        int y[SIZEY] = {1,1,0,0,1,1,0,0,1,1,0,0,1,1,0,0,1,1,0,0,1,1};
        int z[SIZEZ] = {1,1,1,0,0,0,0,1,1,1,1,0,0,0,0,1,1,1,1,0,0,0,0};

        int i,j = 0;
        int m;

        printf("\n");
        for(i = 0; i < 9; i++){
                m  = maj(x[8], y[10], z[10]);

                printf("X: ");
                if(x[8] == m){
                        int t = x[13] ^ x[16] ^ x[17] ^ x[18];
                        for(j = SIZEX-1 ; j >= 0; j--){
                                if(j == 0){
                                        x[j] = t;
                                }else{
                                        x[j] = x[j-1];
                                }

                        }
                }

                for(j = 0; j < SIZEX; j++){
                        printf("%d", x[j]);
                }


                printf("\nY: ");
                if(y[10] == m){
                        int t = y[20] ^ y[21];
                        for(j = SIZEY-1 ; j >= 0; j--){
                                if(j == 0){
                                        y[j] = t;
                                }else{
                                        y[j] = y[j-1];
                                }
                        }

                }
                for(j = 0; j < SIZEY; j++){
                        printf("%d",y[j]);
                	}

		printf("\nZ: ");
                	if(z[10] == m){
                        int t = z[7] ^ z[20] ^ z[21] ^ z[22];
                        for(j = SIZEZ-1 ; j >= 0; j--){
                                if(j == 0){
                                        z[j] = t;
                                }else{
                                        z[j] = z[j-1];
                                }
                        }
                }
                for(j = 0; j < SIZEZ; j++){
                        printf("%d",z[j]);
                }
		
		if(i < 8){
                	int key = x[SIZEX-1] ^ y[SIZEY-1] ^ z[SIZEZ-1];
                	printf("\nKeystream bit = %d ^ %d ^ %d = %d",x[SIZEX-1],y[SIZEY-1],z[SIZEZ-1],key);
                	printf("\n\n");
		}
        }
}

int maj(x ,y, z){
        int m;
        if(x == 0){
                if(y == 0 || z == 0){
                        m = 0;
                }else{
                        m = 1;
                }
        }else{
                if(y == 1 || z == 1){
                        m = 1;
                }else{
                        m = 0;
                }
        }
        return m;
}