Thread: Write a histogram of word length (K&R 1.13 assignment)

Hello everybody,

without any prior knowledge of programming, I have started to learn C thru a book "C Programming Language" by K&R.
While I have followed it with ease up until now, I am stuck at the 1.13 assignment where I have to print a vertical histogram of word length.

I have found the solution on the web, but have hard time figuring out what it really does. Here is the code.

Code:

#include <stdio.h>
#define MAXWL 20
#define MAXWN 30
int main()
{
    int word[MAXWN];            // defines the array of 30 values (max word number)
    int i, c, j, nc, nw;
    
    for (i=0; i < MAXWN; ++i)
        word[i]=0;              // sets all values of array to 0
    
    nw = nc = 0;                // sets counters to 0
    
    while ((c=getchar()) != EOF){
        ++nc;                   // counts characters
        if ( c == ' ' || c == '\t' || c == '\n'){
            word[nw] = nc -1;   // if white space, subtract 1 from counter value
            ++nw;               // than add that value to array position (first 0, than 1 etc.)
            nc = 0;             // reset character counter
        }
    }
    
    for (i=MAXWL; i>=1; --i){   // this prints the histogram
        for (j=0; j<= nw; ++j){ // but how it does it
            if (i<=word[j])     // is beyond me....
                putchar('*');   
            else
                putchar(' ');
        }
        putchar('\n');        
    }
    return 0;
}

Could someone walk me thru the mechanics of the last part of the code so I can understand the process and continue my studies?
Thank you