用C处理多个输入的输出

Question

It's not something trivial but I would like to know the best way to process multiple outputs, for example:

Input

First line of input will contain a number T = number of test cases. Following lines will contain a string each.

Output

For each string, print on a single line, "UNIQUE" - if the characters are all unique, else print "NOT UNIQUE"

Sample Input

 3
 DELHI
 london
 #include<iostream>

Sample Output

 UNIQUE
 NOT UNIQUE
 NOT UNIQUE

So how can I accomplish outputs like that? My code so far is:

 int main(int argc, char *argv[]) 
 {

     int inputs, count=0;
     char str[100];
     char *ptr;

     scanf("%d",&inputs);


     while(inputs-- >0)
     {
         scanf("%s",str);

         for(ptr=str; *ptr!='\0';ptr++)
         {
             if( *ptr== *(ptr+1))
             {
                 count++;
             }
         }
         if(count>0)
         {
             printf("NOT UNIQUE");

         }
         else
         {
             printf("UNIQUE");
         }

     }

 }

But the above will obviously print the output after each input, but I want the output only after entering all the inputs, if the user enters 3, then the user have to give 3 strings and after the output will be given whether the given strings are unique or not. So I want to know how can I achieve the result given in the problem. Also another thing I want to know is, I am using an array of 100 char, which it can hold a string up to 100 characters, but what do I have to do if I want to handle string with no limit? Just declaring char *str is no good, so what to do?

Answer 1

Hope this helps:

#include <stdio.h>

int main(int argc, char *argv[])
{
    int inputs,count=0;
    char str[20];
    scanf("%d",&inputs);
    char *ptr;
    char *dummy;

    while(inputs-- >0)
    {
        scanf("%s",str);

        for(ptr=str; *ptr!='\0';ptr++)
        {
            for(dummy=ptr+1; *dummy != '\0';dummy++)
            {
                if( *ptr== *dummy)
                {
                    count=1;
                }
            }
            if(count == 1)
                break;
        }
        if(count>0)
        {
            printf("NOT UNIQUE");
        }
        else
        {
            printf("UNIQUE");
        }
    }
}

Answer 2

If you want to save stuff for later use, you must store it somewhere. The example below stores up to 10 lines in buf and then points str to the current line:

#include <stdlib.h>
#include <stdio.h>
#include <string.h>    /* for strlen */
#include <ctype.h>     /* for isspace */

int main(int argc, char *argv[]) 
{
    int ninput = 0;
    char buf[10][100];      /* storage for 10 strings */
    char *str;              /* pointer to current string */
    int i;

    printf("Enter up to 10 strings, blank to and input:\n");

    for (i = 0; i < 10; i++) {
        int l;

        str = buf[i];

        /* read line and break on end-of-file (^D) */
        if (fgets(str, 100, stdin) == NULL) break;

        /* delete trailing newline & spaces */
        l = strlen(str);
        while (l > 0 && isspace(str[l - 1])) l--;
        str[l] = '\0';

        /* break loop on empty input */
        if (l == 0) break;
        ninput++;
    }

    printf("Your input:\n");
    for (i = 0; i < ninput; i++) {
        str = buf[i];
        printf("[%d] '%s'\n", i + 1, str);
    }

    return 0;
}

Note the two separate loops for input and output.

I've also rejiggled your input. I'm not very fond of fscanf ; I prefer to read input line-wise with fgets and then analyse the line with strtok or sscanf . The advantage over fscanf is that yout strings may contain white-space. The drawback is that you have a newline at the end which you usually don't want and have to "chomp".

If you want to allow for longer strings, you should use dynamic allocation with malloc , although I'm not sure if it is useful when reading user input from the console. Tackle that when you have understood the basics of fixed-size allocation on the stack.

Other people have already pointed you to the error in your check for uniqueness.