023-array.c

#include <stdio.h>

int main() {
    int c, i, nwhite, nother; // characters, white space
    int ndigit[10]; // ascii '0' - '9'

    nwhite = nother = 0;
    for (i = 0; i < 10; ++i) 
        ndigit[i] = 0;
    //

    while ((c = getchar()) != EOF)
        if (c >= '0' && c <= '9')
            ++ndigit[c-'0'];
        
        else if (c == ' ' || c == '\n' || c == '\t')
            ++nwhite;
        else
            ++nother;
        //
    //
    printf("digits =");
    for(i = 0; i < 10; ++i)
        printf(" %d", ndigit[i]);
    printf(", white space = %d, other = %d\n",
    nwhite, nother);

}