Simple programs

1. Write a program that print word in new line when get white space.
#include <stdio.h>

int main(){
    char s[101];
    while(scanf(" %s", s)!=EOF && s[0]!='#'){ /// if input contains #, it will break the loop. Remove if needed
        printf("%s\n", s);
    }
    return 0;
}

2. Write a program that print word in new line after removing extra space.
/// duplicate

3. Write a program that will count the number of white space in the input string.
#include <stdio.h>

int cntSpace(char *s){
    int cnt=0, i;
    for(i=0; s[i]!='\0'; i++){
        if(s[i]==' ') cnt++;
    }
    return cnt;
}

int main(){
    char s[1001];
    scanf("%[^\n]", s); /// you can use gets(s) as well which is deprecated from standard
    printf("%d\n", cntSpace(s));
    return 0;
}

4. Write a program to find ascii code of a character
#include <stdio.h>

int main(){
    char c;
    scanf("%c", &c);
    printf("%d\n", c);
    return 0;
}

5. Write a program to copy string without strcpy.
#include <stdio.h>
#include <string.h>

void copy(char *b, char *a, int len){
    int i;
    for(i=0; i<len; i++){
        b[i]=a[i];
    }
    b[i]='\0';
}

int main(){
    int sz=101; /// maximum string size, change it as required
    char ar[sz], br[sz];
    scanf("%s",  ar); /// use gets(ar) [non-standard way] or scanf("%[^\n]", s) to scan a whole line
    int len=strlen(ar);
    copy(br, ar, len);
    printf("%s\n", br);
    return 0;
}

6. Write a program to check input is an alphabet or number or special character.
#include <stdio.h>

bool isAlpha(char ch){
    if(ch > 'Z') ch = ch - 'a' + 'A';
    return (ch >= 'A' && ch <= 'Z');
}

bool isDigit(char ch){
    return ( ch >= '0' && ch <= '9' );
}

int main(){
    char c;
    scanf("%c", &c);
    if(isDigit(c)) printf("Digit\n");
    else if(isAlpha(c)) printf("Alphabet\n");
    else printf("Special character\n");
    return 0;
}

7. Write a program to find length of string and number of white space in the input string.
#include <stdio.h>

int cntSpace(char *s){
    int cnt=0, i;
    for(i=0; s[i]!='\0'; i++){
        if(s[i]==' ') cnt++;
    }
    return cnt;
}

int strLen(char *s){
    int cnt=0, i;
    for(i=0; s[i]!='\0'; i++) cnt++;
    return cnt;
}

int main(){
    char s[101];
    scanf("%[^\n]", s); /// you can use gets(s) as well which is deprecated from standard
    printf("String length= %d\n", strLen(s));
    printf("Number of whitespaces= %d\n", cntSpace(s));
    return 0;
}

8. Write a program to make a simple calculator that takes only number as input.
/// need to be more specific, is it just an integer input output or something else?

9. Write a program that will count number of vowel, consonant and digit and whitespace.
#include <stdio.h>

bool isVowel(char c){
    if(c>'Z') c=c-'a'+'A';
    if(c=='A' || c=='E' || c=='I' || c=='O' || c=='U') return 1;
    return 0;
}

bool isCons(char c){
    if(c>'Z') c=c-'a'+'A';
    if(c>='A' && c<='Z') return 1;
    return 0;
}

bool isDig(char c){
    return ( c>='0' && c<='9' );
}

int main(){
    int i=0, v=0, c=0, d=0, sp=0;
    char s[101];
    scanf("%[^\n]", s); /// you can use gets(s) as well which is deprecated from standard
    for(i=0; s[i]1='\0'; i++){
        if(isDig(s[i])) d++;
        else if(isVowel(s[i])) v++;
        else if(isCons(s[i])) c++;
        else if(s[i]==' ') sp++;
    }
    printf("Vowels= %d, Consonants= %d, Digits= %d, Whitespaces= %d\n", v, c, d, sp);
    return 0;
}

10. Write a program that will take a string as input and print whether this is a comment or not.
/// What's the definition of comment?

11. Write a program that will take a line as input and print the line with removing extra space.
#include <stdio.h>

int main(){
    char s[101];
    while(scanf("%s", s)!=EOF && s[0]!='#'){ ///used # as ending line, change/remove as required
        printf("%s", s);
    }
    return 0;
}

12. Write a program for symbol table.
/// what's the definition of symbol table?

13. Write a program for identify token (ex: find operator)
/// need more detail about it

14. Write a program to find the first & follow of grammar.
/// need more detail, it's totally unclear to me