打印字符 C 的 function

Question

My functions change various aspects of a given text. For the following text:

I am young. You are young.All of us are young.
"I think we need some help.Please" HELP. NO,   NO  NO, 
I DO NOT 
    NEED HELP
WHATSOEVER.
"Today's date is
            15/02/2021"...
I am 18 years old. are you 20 years old? Maybe   30 years?

I need it to be prints like this:

I am young. You are young.All of us are young.
"I think we need some help.Please" HELP. NO,   NO  NO, 
I DO NOT 
    NEED HELP
WHATSOEVER.
"Today's date is
            15/02/2021"...
I am  years old. are you  years old? Maybe  years?

For some reason, I have a problem with deleting the numbers and keep in the same state I was prevoisly. this is my code:

main(){
    int state,c,cnt,state1;
    cnt=0;
    state = OUT;
    state1=COUNTINUE;
    printf("PLease insert a sentence\n");
    
    while((c=getchar())!=EOF){
        if(isDigit(c)==TRUE) {
            printf("\b");
        }
    
        if (c=='.')
        {
            putchar(c);
            state =OUT;
        }
        if (c=='"')
        {
            state = IN;
            cnt+=1;
        }
        if(cnt==1)
            state =IN;
    
        if(cnt==2)
        {
            cnt=0;
            putchar(c);
            state = OUT;
        }
    
        if(state == OUT &&isChar(c)==TRUE ){
            if(isUpper(c) ==TRUE)
                putchar(c);
            else
                putchar(toUpper(c));
        
            state = COUNTINUE;
        }
        else if(state==COUNTINUE)
            if(isUpper(c)==FALSE)
                putchar(c);
            else
                putchar(toLower(c));
        else if(state ==IN &&c!='.' &&isDigit(c)==FALSE)
            if(isUpper(c)==FALSE)
                putchar(toUpper(c));
            else
                putchar(c);
    }
}

This is the output Im given:

I am young.You are young.All of us are young."I THINK WE NEED SOME HELP.PLEASE"Help.No,   no  no, 
i do not 
    need help
whatsoever."TODAY'S DATE IS
          "...I am8 years old.Are you0 years old? maybe  0 years?

Answer 1

Looking at the input and required output, I don't understand why would you use toUpper() and toLower() functions. Anyway, your approach is wrong. The below code is enough to skip digits.

while((c=getchar())!=EOF){
    if(isDigit(c)==true){
       continue;
    }
    putchar(c);
}

Now, I assume you want to print digits in "" ie double quotes. In required output it's 15/02/2021 . For that, you would need to use a flag . Set flag=1 if you encounter c='"' which indicates we are inside the "" ie double quotes. If we encounter another c= '"' which indicates end of double quote pair, we set flag=0 . The below code prints digits when inside "" .

flag=0;
while((c=getchar())!=EOF){
        if(c=='"'){
            flag=!flag;//swapping 0 and 1
        }
            if(isDigit(c)==true && flag==0){
               continue;
            }
            putchar(c);
        }