I'm trying to get the following character pattern as follows by only using "for" or "while" loops but no "if" or "if-else" statements: (Mentioned in code block)
It's difficult for me to figure out a way to make the first character appear as blank space or represent it even as a null character. Below is my code:
#include <stdio.h>
#include <conio.h>
int main()
{
char ch[6], j='\0';
int p,q,n,i;
printf("Enter a character\n");
for (n = 0; n < 5; n++)
{
scanf_s(" %c", &ch[n], 1);
}
printf("\n");
for (i = 4; i >= 0; i--)
{
for (p = 4; p >= i; p--)
{
printf("%c", ch[p+1]-1);// _-->A blank space
} // BA
printf("\n"); // CBA
} // DCBA
// EDCBA
_getch();
return 0;
}
I cannot figure out where I'm going wrong — can you help?
I changed this
printf("\n");
for (i = 4; i >= 0; i--)
{
for (p = 4; p >= i; p--)
{
printf("%c", ch[p+1]-1);
}
printf("\n");
}
for this
printf("\n_\n");
for (i = 1; i < 5; i++) {
for (p = i; p >= 0; p--) {
printf("%c", ch[p]);
}
printf("\n");
}
And got this output (console):
Enter a character
ABCDE
_
BA
CBA
DCBA
EDCBA
#include <stdio.h>
#include <conio.h>
#define SIZE 5
int main(void){
char ch[SIZE+1] = {0};
int i;
printf("Enter a character\n");
for (i = SIZE-1; i >= 0; --i){
scanf_s(" %c", &ch[i], 1);
}
printf(" \n");
for (i = SIZE-2; i >= 0; --i) {
printf("%s\n", ch + i);
}
_getch();
return 0;
}
Related
As stated in the title I am trying to find all lower-case letters that are not in a series of words. There are no upper-case letters, digits, punctuation, or special symbols.
I need help fixing my code. I am stuck and do not know where to go from here.
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main(void){
int letters[26];
char words[50];
int i = 0, b = 0;
printf("Enter your input : ");
scanf("%s", words);
for(i = 0; i < 26; i++){
letters[i] = 0;
}
while(!feof(stdin)){
for(b = 0; b < strlen(words) - 1; b++){
letters[ words[b] - 'a']++;
scanf("%s", words);
}
}
printf("\nMissing letters : %c ", b + 97);
return 0;
}
My output is giving me some random letter that I do not know where it is coming from.
Here is a working first implementation.
As well as the comments that have already been made, you should use functions wherever possible to separate out the functionality of the program into logical steps. Your main function should then just call the appropriate functions in order to solve the problem. Each function should be something that is self contained and testable.
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define MAX_INPUT 20 /* Max input to read from user. */
char *readinput(void);
void find_missing_lower_case(char *, int);
int main()
{
char *user_input = readinput();
int len_input = strlen(user_input);
printf("user input: %s\n", user_input);
printf("len input: %d\n", len_input);
find_missing_lower_case(user_input, len_input);
/* Free the memory allocated for 'user_input'. */
free(user_input);
return 0;
}
char *readinput()
{
char a;
char *result = (char *) malloc(MAX_INPUT);
int i;
for(i = 0; i < MAX_INPUT; ++i)
{
scanf("%c", &a);
if( a == '\n')
{
break;
}
*(result + i) = a;
}
*(result + i) = '\0';
return result;
}
void find_missing_lower_case(char *input, int len_input)
{
int a = 97; /* ASCII value of 'a' */
int z = 122; /* ASCII value of 'z' */
int lower_case_chars[26] = {0}; /* Initialise all to value of 0 */
/* Scan through input and if a lower case char is found, set the
* corresponding index of lower_case_chars to 1
*/
for(int i = 0; i < len_input; i++)
{
char c = *(input + i);
if(c >= a && c <= z)
{
lower_case_chars[c - a] = 1;
}
}
/* Iterate through lower_case_chars and print any values that were not set
* to 1 in the above for loop.
*/
printf("Missing lower case characters:\n");
for(int i = 0; i < 26; i++)
{
if(!lower_case_chars[i])
{
printf("%c ", i + a);
}
}
printf("\n");
}
I figured it out and this is the code I used.
int main(void)
{
int array[26];
char w;
int i=0;
for(i=0; i<26; i++) {
array[i]=0; }
printf("Enter your input: ");
scanf("%c", &w);
while(!feof(stdin)) {
array[w-97] = 1;
scanf("%c", &w); }
printf("Missing letters: ");
for(i=0; i<26; i++) {
if(array[i] == 0) {
printf("%c ", i+97); }
}
printf("\n");
return 0;
}
I'm learning basics in coding. Can any one say what went wrong with my code
Prob:Given a string, S, of length N that is indexed from 0 to N-1 , print its even-indexed and odd-indexed characters as 2 space-separated strings on a single line
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>
char input[100], final[100];
int main()
{
int num, i, j;
char even[50], odd[50], space[] = " ";
scanf("%d", &num);
for (i = 0; i < num; i++)
{
int k = 0, p = 0;
scanf(" %[^\n]s", input);
for (j = 0; input[j] != '\0'; j++)
{
if (j % 2 == 0)
{
even[k] = input[j];
k++;
}
else
{
odd[p] = input[j];
p++;
}
}
strcat(final, even);
strcat(final, space);
strcat(final, odd);
}
printf("%s", final);
}
I am having trouble doing my homework.
I am doing an RSA application which can encrypt and decrypt.
The problem is that after I Input things to encrypt the results are weird and I can't decrypt anything. This is because when I copied the results of encryption which are symbols, I got more weird stuffs.
I'm guessing it has something to do with my formula getting negative ASCIIs as results.
Below is what I tried, and, in order to understand what I meant by weird, just compile and try it out(I have some unused stuffs which I haven't removed yet):
Output:
Code:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <math.h>
#define boolean int
#define true 1
#define false 0
//===================================================//
int p = 0;
int q = 0;
int n = 0;
int m = 0;
int divider = 2;
int tempdivider = 2;
int initial = 0;
int x = 0;
int y = 0;
char msg[100];
char alphabet[27];
//===================================================//
void cls();
void menu();
void init();
void reinit();
void inputencrypt();
//int encrypt(int num);
void encrypt();
char decrypt(char text[]);
int fpb(int num);
int d(int num);
int primecheck(int a);
boolean checkdigit(char text[]);
//===================================================//
int main() {
frontpage();
init();
menu();
getchar();
return 0;
}
//===================================================//
void cls() {
for (int i = 0;i < 25;i++) {
printf("\n");
}
}
//===================================================//
boolean checkdigit(char text[]) {
int len = strlen(text);
for (int i = 0;i < len;++i) {
if (text[i]<'0' || text[i]>'9') {
return false;
}
}
return true;
}
int primecheck(int a) {
if (a == 1) {
return false;
}
for (int i = 2;i < a;i++) {
if (a%i == 0) {
return false;
}
}
return true;
}
//===================================================//
void reinit() {
for (int i = 1;i < 27;i++) {
alphabet[i] = 'a' + i - 1;
}
p = 0;
q = 0;
n = 0;
m = 0;
divider = 2;
tempdivider = 2;
initial = 120;
x = 0;
y = 0;
}
void init() {
reinit();
do {
printf("p = ");
scanf("%d", &p);fflush(stdin);
if (!primecheck(p)) {
printf("must be prime number! \n");
}
} while (!primecheck(p));
do {
printf("q = ");
scanf("%d", &q);fflush(stdin);
if (!primecheck(q)) {
printf("must be prime number! \n");
}
} while (!primecheck(q));
n = p*q;
m = (p - 1)*(q - 1);
initial = m;
x = fpb(m);
y = d(m);
printf("n = %d\n", n);
printf("m = %d\n", m);
printf("e = %d\n", x);
printf("d = %d\n", y);
system("pause");
}
//===================================================//
void menu() {
char input[2];
int input1 = 0;
do {
do {
cls();
printf("main menu\n");
printf("================\n");
printf("1. encrypt\n");
printf("2. decrypt\n");
printf("3. exit\n");
printf(">> ");
scanf("%s", input);fflush(stdin);
if (checkdigit(input)) {
input1 = atoi(input);
}
} while (!checkdigit(input));
switch (input1) {
case 1:
int c;
char encrypted[100];
char word[100];
printf("input word to encrypt : ");
scanf(" %[^\n]", word);fflush(stdin);
for (int i = 0;i < strlen(word);i++) {
if (word[i] == ' ') {
encrypted[i] = ' ';
//i++;
}
else {
for (int j = 1;j < 27;j++) {
if (word[i] == alphabet[j]) {
c = 0;
c = pow(j, x);
c = c%n;
encrypted[i] = c;
break;
}
}
}
}
printf("\n\nWord ASCII [ ");
for (int i = 0;i < strlen(word);i++) {
//printf("%d", c);
printf("%d ", word[i]);
}
printf(" ]\n");
printf("\n\nEncrypted ASCII [ ");
for (int i = 0;i < strlen(word);i++) {
//printf("%d", c);
printf("%d ", encrypted[i]);
}
printf(" ]\n");
printf("\n\nEncrypted [ ");
for (int i = 0;i < strlen(word);i++) {
//printf("%d", c);
printf("%c", encrypted[i]);
}
printf(" ]");
printf("\n\n\n");
system("pause");
break;
case 2:
int temp[100];
char decrypted[100];
char wordx[100];
int h;
printf("input word to decrypt : ");
scanf(" %[^\n]", wordx);fflush(stdin);
for (int i = 0;i < strlen(wordx);i++) {
temp[i] = wordx[i];
//temp[i] -= 97;
//printf("%d ::: %c\n", temp[i], temp[i]);
}
for (int i = 0;i < strlen(wordx);i++) {
if (wordx[i] == ' ') {
decrypted[i] = ' ';
}
else {
h = 0;
h = pow(temp[i], y);
h = h%n;
decrypted[i] = h;
for (int j = 1;j < 27;j++) {
if (decrypted[i] == j) {
decrypted[i] = alphabet[j];
}
}
}
}
printf("\n\nWord ASCII [ ");
for (int i = 0;i < strlen(wordx);i++) {
//printf("%d", c);
printf("%d ", wordx[i]);
}
printf(" ]\n");
printf("\n\nDecrypted ASCII [ ");
for (int i = 0;i < strlen(wordx);i++) {
//printf("%d", c);
printf("%d ", decrypted[i]);
}
printf(" ]\n");
printf("\n\nDecrypted [ ");
for (int i = 0;i < strlen(wordx);i++) {
//printf("%d", decrypted[i]);
printf("%c", decrypted[i]);
}
printf(" ]");
printf("\n\n\n");
system("pause");
break;
}
} while (input1 != 3);
}
//===================================================//
int fpb(int num) {
if (!primecheck(num)) {
if (num%divider == 0) {
num = num / divider;
divider = 2;
}
else {
divider++;
}
fpb(num);
}
else if (primecheck(num)) {
if (!primecheck(num + divider)) {
tempdivider++;
divider = tempdivider;
num = initial;
fpb(num);
}
else {
return num + divider;
}
}
}
int d(int num) {
for (int i = 1;i < num;i++) {
if ((x*i) % num == 1) {
return i;
}
}
}
You have a general comprehension problem. Your console is only able to represent 96 characters correctly (known as printable 7bit-ASCII characters, 0x20 to 0x7F), but a byte can hold 255 different values. Your encryption algorithm does not care about this limited range, it will encrypt any value in the range [0..255] into another value in the range [0..255]. So your ASCII input characters will most likely be encrypted into values that cannot be represented by your console correctly. Copy&Past will not work correctly for non-printable characters (like 0x0B, which is a tab).
But now you will wonder: Why does that work for e.g. E-Mails? Simply: Because those characters are converted into an ASCII representation. Please google a bit for Base64 encoding.
As an alternative, you can always stream your encrypted characters into a file and later read back from that. This way you will bypass the limitations of your console.
Btw: Please have a look at the documentation of printf() and you will know, why you get those negative values.
The encrypt option has these three statements consecutively
c = 0;
c = pow(j, x);
c = c%n;
and the last of those will leave c in the range 0..(n-1).
Apart from that, there is no else clause and int c; can remain uninitialised.
So all in all it is inevitable that when you print c values as characters you will get "weird" results.
As for negative values, char encrypted[100]; is probably signed char so any integer value in the range 128..255 assigned to that, although undefined behaviour, may possibly show up as a negative number because the signed char is promoted back to int when passed as format %d to printf.
Originally I was using scanf, but I was running into the newline char getting stuck in the stdin. Everything I have read was saying to switch to fgets and use sscanf instead. With that, I decided to switch to that...but that still is not working. Below you will find my code. My question is, what am I doing wrong with my fgets and sscanf that is causing it to not wait for the user input?
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct f_in{
char outline;
int lines;
int rows;
int num_args;
} F_IN;
typedef struct args_in {
char in_string[20];
int t_format;
} ARGS_IN;
void printInterface(char argQs[5][50], char argChar);
int main(int argv, char** argc){
char defaultQuestions[5][50] = { { "1) What char for border?" }
, { "2) Add question" }
, { "3) Remove Question" }
, { "4) Print last answers" }
, { "5) Exit" } };
int commandEntry, exitFlag;
char borderChar = '*', addQ[50],userInp[1];
exitFlag = 1;
while (exitFlag){
printInterface(defaultQuestions, borderChar);
printf("Enter the integer value for the command you wish to select: ");
fgets(userInp, sizeof(userInp),stdin);
sscanf(userInp,"%d", &commandEntry);
printf("\nYou selected: %s\n", defaultQuestions[commandEntry - 1]);
userInp[0] = 0;
if (commandEntry == 1){
printf("Please enter the character you wish to be the border: ");
fgets(userInp,sizeof(userInp),stdin);
sscanf(userInp,"%c",&borderChar);
}
else if (commandEntry == 2){
printf("What question would you like to add? (only enter 50 char max)\n");
fgets(addQ, 50, stdin);
printf("This was your question: %s", addQ);
}
else if (commandEntry == 5){
printf("Goodbye!\n");
exitFlag = 0;
}
}
return 0;
}
void printInterface(char argQs[5][50], char argChar){
int i, j;
int lineCnt = 13;
int borderLen = 75;
for (i = 0; i<100; i++){
printf("\n");
}
for (i = 0; i<lineCnt; i++){
if (i == 0 || i == lineCnt - 1){
for (j = 0; j<borderLen; j++){
printf("%c", argChar);
}
printf("\n");
}
else if (i >= 3 && i <= 10){
printf("%c %s", argChar, argQs[i - 3]);
for (j = 0; j < ((borderLen - strlen(argQs[i - 3]))-6); j++){
printf(" ");
}
printf("%c\n", argChar);
}
else{
for (j = 0; j<borderLen; j++){
if (j == 0){
printf("%c", argChar);
}
else if (j == (borderLen - 1)){
printf("%c\n", argChar);
}
else{
for (j = 0; j<borderLen; j++){
if (j == 0){
printf("%c", argChar);
}
else if (j == (borderLen - 1)){
printf("%c\n", argChar);
}
else{
printf(" ");
}
}
}
}
for (i = 0; i<10; i++){
printf("\n");
}
}
"userInp[1] only allows enough memory to store the terminating '\0'"
- user312023
I am reading the input and trying to print all the input lowercase character in a graphical format, am able to read it and keep track of the number of time each character repeats but not able to print it in a graphical way,can u pls help me out. Here is my code
#include <stdio.h>
#include <ctype.h>
int print_fun(int);
int main() {
int ch = 0, i = 0;
int char_count[26] = {0};
printf("\nNOTE:PRESS * TO EXIT\n");
while((ch = getchar()) != '*') {
if(islower(ch))
char_count[ch - 'a']++;
}
printf("\n");
for(i = 0; i < 26; i++)
//printf("%c:%d\n",'a'+ i, char_count[i]);
//printf("%c:\n", 'a'+ i, print_star(char_count[i]));
printf("%c:\n",print_star(char_count[i]),'a'+ i);
printf("\n");
return 0;
}
int print_star(int value) {
int i = 0;
for(i = 0; i < value; i++)
printf("*");
}
o/p: aaxyyz
a:**
b:
c:
...
...
x:*
y:**
z:*
Your printf call is missing an format argument, you have this:
printf("%d:%c\n",print_star(char_count[i]),'a'+ i);
but you are passing two arguments to printf, as far as I can tell this is what you meant:
printf("%d:%c\n",print_star(char_count[i]),'a'+ i);
Also, print_star has a return value of int but you do not have a return statement, I think you meant to return i and in that case you should add:
return i ;
at the end. The behavior without a return at the end is undefined. Finally, it looks like you have a typo in forward declaration, this:
int print_fun(int);
should be:
int print_star(int value );
#include <stdio.h>
#include <ctype.h>
//int print_fun(int);
void print_star(int);
int main(void){
int ch = 0, i = 0;
int char_count[26] = {0};
printf("\nNOTE:PRESS * TO EXIT\n");
while((ch = getchar()) != '*'){
if(islower(ch))
char_count[ch - 'a']++;
}
printf("\n");
for(i = 0; i < 26; i++){
printf("%c:",'a'+ i);
print_star(char_count[i]);
printf("\n");
}
printf("\n");
return 0;
}
void print_star(int value){
int i = 0;
for(i = 0; i < value; i++)
printf("*");
}