Actually recently i found a problem where i need to count occurrence a given(by oj) char in a given string(with test case).So i write this code but output is not as i desired.I'm a beginner so i'll be greatly thankful for any kind of instructive advice or help.THANK YOU.
#include<stdio.h>
#include<string.h>
int main ()
{
int ara [123];
char s[1000];
int l, j, i, len;
char c;
scanf ("%d\n", &l);
while (l >= 0){
for (i = 65; i <= 122; i++)
{
ara[i] = 0;
}
fgets(s, 1000, stdin);
len = strlen(s);
for (i = 0;i <= len; i++)
{
ara[s[i]]++;
}
scanf(" %c\n", &c);
j = c;
printf("count : %d\n", ara[j]);
l--;
}
return 0;
}
The problem is that scanf is leaving a newline in the input to be read as the target sentence.
You can get around this by using fgets and sscanf instead. I also added some cues to make it easier to know what is expected.
#include <stdio.h>
#include <string.h>
int main (void)
{
int ara [128]; // increased array size
char s[1000];
char t[10];
int l, j, i, len;
char c;
printf("Enter how many loops:\n");
fgets(t, sizeof t, stdin); // replace scanf
sscanf (t, "%d\n", &l); // with sscanf
while (l > 0){ // changed end test
for (i = 'A'; i <= 'z'; i++) // replaced magic numbers
{
ara[i] = 0;
}
printf("Enter the string:\n");
fgets(s, sizeof s, stdin);
len = strlen(s);
for (i = 0;i <= len; i++)
{
ara[s[i]]++;
}
printf("Enter the letter:\n");
fgets(t, sizeof t, stdin); // replace scanf
sscanf (t, "%c\n", &c); // with sscanf
j = c;
printf("count : %d\n", ara[j]);
l--;
}
return 0;
}
Program session
Enter how many loops:
2
Enter the string:
one two three four
Enter the letter:
o
count : 3
Enter the string:
three seven
Enter the letter:
e
count : 4
Note that ideally, you should also check the function return values from fgets and sscanf.
Related
My first program. I would like it if the user enters a word made of letters and then it uses my loop function to output mixed up even and odd characters. Currently I cannot get it to compile. Bonus points if someone can show me how to loop the users input so after it asks the size to make the array, it prompts the user that many times for an "element" or word so that the function can scramble it and output it.
#include <stdio.h>
char transform(char str[]);
int main()
{ //Declare an array and size variable
int size = 0;
char str[size];
printf("How many elements?");
scanf("%d", &size);
printf("Please type an element: ");
//Get input from user
str[0] = scanf("%s", str);
transform(str);
printf("Please type another element: ");
//Get another input from user
str[1] = scanf("%s", str);
transform(str);
//This is the loop function that I programmed
char transform(char str[]);
{
//Loop that prints even characters
for (int i = 0; str[i] != '\0'; i++)
{
if(i % 2 == 0)
{
printf("%c", str[i]);
}
} //Space between even/odd characters
printf(" ");
//Loop that prints odd characters
for (int i = 0; str[i] != '\0'; i++)
{
if(i % 2 != 0)
{
printf("%c", str[i]);
}
}
printf("\n");
return 0;
}
}
#include <stdlib.h>
#include <stdio.h>
char transform(char str[]);
int main()
{ //Declare an array and size variable
int size = 0;
printf("How many elements?");
scanf("%d", &size);
for (int i = 0; i < size; ++i)
{
printf("Please type an element: ");
char str[2048]; //declare a wide buffer to be able to store lots of chars
scanf("%s", str);
transform(str);
}
return 0;
} //end your main here, by putting closing brace
char transform(char str[]) //define transform without semicolon, and outside of main
{ //This is the loop function that I programmed
//Loop that prints even characters
for (int i = 0; str[i] != '\0'; i++)
{
if (i % 2 == 0)
printf("%c", str[i]);
} //Space between even/odd characters
printf(" ");
//Loop that prints odd characters
for (int i = 0; str[i] != '\0'; i++)
{
if (i % 2 != 0)
printf("%c", str[i]);
}
printf("\n");
return 0;
}
This is my code.
#include<stdio.h>
#include<string.h>
int main()
{
int n, i;
char ch[100];
scanf("%d", &n);
for(i = 0; i < n; i++){
scanf(" %c", &ch[i]);
}
printf("%s\n", strupr(ch));
return 0;
}
At first, I want to take the size of the character array in n variable. After, i want to take n character's and assign the array. The output comes from this program is right but it also produce some garbage values.
For example:
5
s d g h f
Output: SDGHFC└U▄■`
How can i ignore the garbage values from my output?
Simply initialize your array ch[] to all zeros. I.E.
for (i = 0; i < 100; i += 1) { ch[i] = '\0'; }
Put this line just after the declaration of ch[].
As you are reading character the spaces you are providing in your input, will also be considered as characters, and strupr(c) will give some shaggy output, also you have to manually provided null character at the end of your character array. Below program might help you find your answer
#include<stdio.h>
#include<string.h>
int main()
{
int n, i;
scanf("%d", &n);
fflush(stdin);
char ch[100];
for(i = 0; i < n; i++){
char temp;
scanf("%c", &temp);
if(temp != '\n')
ch[i] = temp;
else
break;
}
ch[n] = '\0';
printf("%s\n", strupr(ch));
return 0;
}
Your Input should look like
5
sdghf
To give input with spaces. Program will look like.
#include<stdio.h>
#include<string.h>
int main()
{
int n, i;
scanf("%d", &n);
fflush(stdin);
char ch[100];
char temp;
i = 0;
while(scanf("%c", &temp)){
if(temp == ' ')
continue;
if(temp != '\n')
ch[i++] = temp;
else
break;
}
ch[i] = '\0';
printf("%s\n", strupr(ch));
return 0;
}
Now, you can give your character in any arrangement as you want.
I want to do a program that ask to the user to give one character, then enter... until he wants to stop by pressing enter and no caracters.
Then, the program will say: "you gave the caracters ...."
for example:
give the caracter 1: k + enter
give the caracter 2: l + enter
give the caracter 3: just enter ('\n')
result: You gave the caracters: kl
My code doesnet work because when i just press enter, nothing happen. Here is the code:
#include <stdio.h>
#define N 1000
int main() {
int i = 0;
int j = 0;
char str[N];
while (str[i] != '\n') {
printf("element number str[%d] : ", i);
scanf("%s", &str[i]);
i++;
}
printf("The string is: ");
while (j < i) {
printf("%s", str[j]);
j += 1;
}
return 0;
}
You can do it with c = getchar(); or c = fgetc(stdin) function:
#include <stdio.h>
#define N 1000
int
main ()
{
int i = 0;
int j = 0;
int c;
char str[N];
while (1)
{
c = fgetc(stdin); // or c = getchar();
if ( (c != EOF) && (c != 0x0A ) ) // 0x0A = 'nl' character
{
str[i] = (char) c;
printf ("element number str[%d]=%c \n", i, str[i++] );
}
else
{
str[i] = 0;
break;
}
}
printf ("The string is: %s", str);
return 0;
}
OUTPUT:
This is my string!
element number str[1]=T
element number str[2]=h
element number str[3]=i
element number str[4]=s
element number str[5]=
element number str[6]=i
element number str[7]=s
element number str[8]=
element number str[9]=m
element number str[10]=y
element number str[11]=
element number str[12]=s
element number str[13]=t
element number str[14]=r
element number str[15]=i
element number str[16]=n
element number str[17]=g
element number str[18]=!
The string is: This is my string!
Or you can use your original scanf("%s", &str1);
#include <stdio.h>
#define N 1000
int main ()
{
int i = 0;
int k = 0;
int c;
int len;
char str[N];
char str1[N];
scanf("%s", &str1);
len = strlen(str1);
for(k = 0; k < len; k++)
{
c = str1[k];
if ( (c != EOF) && c != '\n') // EOF will work for ^D on UNIX
{
str[i] = (char) c;
printf ("element number str[%d]=%c \n", i, str[i++] );
}
else
{
str[i] = 0;
break;
}
}
printf ("The string is: %s", str);
return 0;
}
OUTPUT:
12345
element number str[1]=1
element number str[2]=2
element number str[3]=3
element number str[4]=4
element number str[5]=5
The string is: 12345
As stated in this answer scanf will not return until you give it a string, i.e. it skips whitespace.
As suggested in the answer and in general, using fgets is the better option.
Edit: A way to accomplish what you want would look like this:
#include <stdio.h>
#define N 1000
int main() {
int i = 0;
int j = 0;
char str[N];
do {
printf("element number str[%d] : ", i);
fgets(&str[i], 3, stdin);
i++;
} while (str[i - 1] != '\n');
printf("The string is: ");
while (i > j) {
printf("%c", str[j]);
j++;
}
return 0;
}
In the fgets you use the number 3 because pressing enter gives both a newline character [/n] and a return carriage [/r].
I am new to C programming so please do forgive my naivety. The following program when outputted fails to print the last character of the input string as the first character of the output string.
For example:
Enter no. of elements: 5
Enter string: hello
The reversed string is: lleh
Why is the o not printing?
#include <stdio.h>
int main() {
printf("Enter no. of elements: ");
int n;
scanf("%d", &n);
char string[10000];
printf("Enter string: ");
for (int i = 0; i < n; i++) {
scanf("%c", &string[i]);
}
printf("The reversed string is: ");
for (int i = (n - 1); i >= 0; i--) {
printf("%c", string[i]);
}
printf("\n");
return 0;
}
There is a side effect you take care of:
After scanf("%d", &n);, there is a pending newline in the input stream buffer.
When you later input n characters, scanf("%c", &string[i]) first reads the pending newline, then the n-1 first characters you type and the remainder of your input stays in the input buffer.
scanf() is a very clunky function. It is difficult to use properly.
Here is a way to fix your problem:
#include <stdio.h>
int main() {
char string[10000];
int i, n, c;
printf("Enter no. of elements: ");
if (scanf("%d", &n) != 1 || n < 0 || n > 10000)
return 1;
// read and discard pending input
while ((c = getchar()) != '\n' && c != EOF)
continue;
printf("Enter string: ");
for (i = 0; i < n; i++) {
if (scanf("%c", &string[i]) != 1)
break;
}
// the above loop could be replaced with a single call to fread:
// i = fread(string, 1, n, stdin);
printf("The reversed string is: ");
while (i-- > 0) {
printf("%c", string[i]);
}
printf("\n");
return 0;
}
Your scanf() should start with a space( more info about that ). Here is the code:
#include <stdio.h>
int main() {
printf("Enter no. of elements: ");
int n;
scanf(" %d", &n);
char string[10000];
printf("Enter string: ");
for (int i = 0; i < n; i++) {
scanf(" %c", &string[i]);
}
/* Just to be safer. */
string[n] = '\0';
printf("The reversed string is: ");
for (int i = (n-1); i >= 0; i--) {
printf("%c", string[i]);
}
printf("\n");
return 0;
}
Adding the space to the format string enables scanf to consume the
newline character from the input that happens everytime you press
return. Without the space, string[i] will receive the
char '\n'
So, merely one space is put before format specifier %c at line 11.
scanf(" %c", &string[i]);
This program need to read two strings, this two strings will be passed to the "confirm" function, they will be read and the the function will have to find a word in common.
But in the main i cant read the "string2" string! No matter how many getchar i insert.
#include <stdio.h>
#include <string.h>
void confirm(char string1[],char string2[]){
char word[20];
char w_aux[20];
int i, j, k, l, m;
int len1, len2;
int find;
i = 0;
len1 = strlen(string1);
len2 = strlen(string2);
while (i < len1){
j = 0;
while ((string1[i] != ' ') && (i < len1)){
word[j] = string1[i];
i++;
j++;
}
word[j] = '\0';
k = 0;
find = 0;
while((k < len2) && (find == 0)){
l = 0;
while ((string2[k] != ' ') && (k < len2)){
w_aux[l] = string2[k];
k++;
l++;
}
w_aux[l] = '\0';
if (j == l){
m = 0;
while((word[m] == w_aux[m]) && (m<j)){
m++;
}
if (m == j){
find = 1;
}
}
k++;
}
i++;
}
printf("%s\n", word);
}
int main (){
char string1[20];
char string2[20];
printf("Type the first text: \n");
scanf("%[^\n]s", string1);
printf("Type the second text: \n");
scanf("%[^\n]s", string2);
getchar();
confirm(string1, string2);
return 0;
}
Use getchar after input of string 1 for \n:
printf("Type the first text: \n");
scanf("%[^\n]", string1);
getchar(); //here
printf("Type the second text: \n");
scanf("%[^\n]", string2);
Just change the format specifier to "%19[^\n]*c", it will take the trailing '\n' character away.