How to Understand a C Code with Nested Loops for Pattern Problems?

Question

Lately, I been learning c and I am into loop with pattern problems, There is one code I am not able to understand, Would somebody please explain briefly about this

#include<stdio.h>
#include<conio.h>
int main(){ 
      int i,j,k,count=1;
      for(i=1;i<=4;i++){  
             for(j=4;j>i;j--){ 
                 printf(" ");
                }
             for(k=1;k<=i;k++){
                 printf("%d ",count);
                 count++;   
                }  
        printf("\n");    
    }
   getch();
   return 0;
   }

Here's This output :

I tried to understand but failed

Welcome to SO. For future reference: [Please do not upload images of code/data/errors.](//meta.stackoverflow.com/q/285551) — 001, May 30 '23 at 15:32
Now is probably a good time to learn to use a debugger. Step through the code, watching the values of `i, j, k`. [What is a debugger and how can it help me diagnose problems?](https://stackoverflow.com/q/25385173) — 001, May 30 '23 at 15:34
Formatting the code with consistent indentation would be a good start. It is much easier to analyze code whose lexical form reflects its logical structure. — John Bollinger, May 30 '23 at 15:40
Try systematically replacing variable names with more meaningful ones, and re-reading the code. Substitute `rowNumber` for `i` throughout. Substitute `columnNumber` for `k` throughout. `j` doesn't have an easy natural-language interpretation—the closest might be `charactersRemainingBeforeWeWillHavePassedTheMiddle`. — jez, May 30 '23 at 15:48

score 1 · Answer 1 · answered May 30 '23 at 16:40

A line by line explanation of the code would be ideal. The first two lines in your file contains the statements

#include<stdio.h>
#include<conio.h>

You have imported the standard C Library stdio.h that let's you use the stdin and stdout functions for reading input from the user and displaying it to the user. You have also imported the header file conio.h which lets you read a character at a time without having to hit the Enter Key using the function getch().

int main(){
//code
}

The function above is the main entry point of your program and this function is universal to most of the programming languages. It is where you write the TODO logic of your application.

int i,j,k,count=1;
for(i=1;i<=4;i++){  
    for(j=4;j>i;j--){ 
         printf(" ");
        }
     for(k=1;k<=i;k++){
         printf("%d ",count);
         count++;   
                }  
     printf("\n");    
    }

In the code segment above inside your main, you have declared a union of integer variables for use inside the loops and the count variable whose value is used to print the pyramid of numbers.

The outermost for loop is used to print line breaks. The next loop nested inside it, does backward iteration and has been used to print spaces between more than one numbers that are on the same line. The last nested for loop is used to do the printing of the actual numbers to the console to form the number triangle.

return 0;

The line above returns an exit code to the operating system. It is useful to return codes to the operating system for debugging and tracing errors.

How to Understand a C Code with Nested Loops for Pattern Problems?

1 Answers1