String Interview Questions

QUESTION-11 Remove all Characters in Second String which are present in First String

Answer-

#define CHAR_SIZE 26
 
void alphacheck(char *, int []);
void create(char [], char [], int[]);
 
int main()
{
    char str1[50], str2[50];
    int a1[CHAR_SIZE] = {0};
    char str2_rem[50];
 
    printf("Enter string1: ");
    scanf("%s", str1);
    printf("Enter string2: ");
    scanf("%s", str2);
    alphacheck(str1, a1);
    create(str2_rem, str2, a1);
    printf("On removing characters from second string we get: %s\n", str2_rem);
 
    return 0;
}
 
void alphacheck(char *str, int a[])
{
    int i, index;
 
    for (i = 0; i < strlen(str); i++)
    {
        str[i] = tolower(str[i]);
        index = str[i] - 'a';
        if (!a[index])
        {
            a[index] = 1;
        }
    }
    printf("\n");
}
 
void create(char str_rem[], char str[], int list[])
{
    int i, j = 0, index;
 
    for (i = 0; i < strlen(str); i++)
    {
        index = str[i] - 'a';
        if (!list[index])
        {
            str_rem[j++] = str[i];
        }
    }
    str_rem[j] = '\0';
}

QUESTION-12 Reverse the String using Recursion

Answer-

void reverse(char [], int, int);
int main()
{
    char str1[20];
    int size;
 
    printf("Enter a string to reverse: ");
    scanf("%s", str1);
    size = strlen(str1);
    reverse(str1, 0, size - 1);
    printf("The string after reversing is: %s\n", str1);
    return 0;
}
 
void reverse(char str1[], int index, int size)
{
    char temp;
    temp = str1[index];
    str1[index] = str1[size - index];
    str1[size - index] = temp;
    if (index == size / 2)
    {
        return;
    }
    reverse(str1, index + 1, size);
}

QUESTION-13 Reverse every Word of given String

Answer-

void main()
{
    int i, j = 0, k = 0, x, len;
    char str[100], str1[10][20], temp;
 
    printf("enter the string :");
    scanf("%[^\n]s", str);
 
    for (i = 0;str[i] != '\0'; i++)
    {
        if (str[i] == ' ')
        {
            str1[k][j]='\0';
            k++;
            j=0;
        }
        else
        {
            str1[k][j]=str[i];
            j++;
        }
    }
    str1[k][j] = '\0';
 
    for (i = 0;i <= k;i++)
    {
        len = strlen(str1[i]);
        for (j = 0, x = len - 1;j < x;j++,x--)
        {
            temp = str1[i][j];
            str1[i][j] = str1[i][x];
            str1[i][x] = temp;
        }
    }
    for (i = 0;i <= k;i++)
    {
        printf("%s ", str1[i]);
    }
}

QUESTION-14 Delete All Repeated Words in String

Answer-

 
void main()
{
    char a[100], b[20][20];
    int i, j = 0, k = 0, n, m;
 
    printf("enter the string\n");
    scanf("%[^\n]s", a);
    for (i = 0;a[i] != '\0';i++)
    {
        if (a[i] == ' ')
        {
            b[k][j] = '\0';
            k++;
            j = 0;
        }
        else
        {
            b[k][j] = a[i];
            j++;
        }
    }
    b[k][j] = '\0';
    for (i = 0;i <= k;i++)
    {
        for (j = i + 1;j <= k;j++)
        {
            if (strcmp(b[i], b[j]) == 0)
            {
                for (m = j;m <= k;m++)
                    strcpy(b[m], b[m + 1]);
                k--;
            }
        }
    }
    for (n = 0;n <= k;n++)
    {
        printf("%s\n", b[n]);
    }
}

QUESTION-15 Reverse the String using Both Recursion and Iteration

Answer-

void disp_str1_rec(char *);
 
void main()
{
    char str1[100], *ptr;
    int len1 = 0, i;
    char ch;
    printf("Enter the string:\n");
    scanf("%[^\n]s", str1);
    ptr = str1;
    len1 = strlen(str1);
    printf("Using iteration:\n");
    for (i = len1 - 1; i >= 0;i--)            {
 
        ch = str1[i];
        printf("%c", ch);
    }
    printf("Using recurssion:\n");
    disp_str1_rec(ptr);
}
 

void disp_str1_rec(char *stng)
{
    char ch;
    if (*stng != '\0')
    {
        ch = *stng;
        stng++;
        disp_str1_rec(stng);
        printf("%c", ch);
    }
    else
    return;
}