ZigZag Conversion

Link

It took me some time to understand the problem but as soon as I figured out what it was asking, all I had to do was find a pattern and the solution became clear.

Full Solution in Java:

public class Solution {
    public String convert(String s, int numRows) {
        StringBuilder sb = new StringBuilder();
        
        char[] c = s.toCharArray();
        
        int stepOne = 0;
        int stepTwo = 0;
        
        
        if(numRows==1){
            return s;
        }
        
        for(int i=1; i<=numRows; i++){
            if(i==1 || i==numRows){
                stepOne = 2*(numRows-1);
                stepTwo = 2*(numRows-1);
            }
            else{
                stepOne = 2*(numRows-i);
                stepTwo = 2*(i-1);
            }
            
            int pos = i-1;
            for(int j=0; j< c.length; j++){
                if(pos>=c.length){
                    break;
                }
                
                if(j%2==0){
                   sb.append(c[pos]);
                   pos+=stepOne;
                }
                
                else{
                    sb.append(c[pos]);
                    pos+=stepTwo;
                }
            }
            
        }
        
        return sb.toString();
        
        
    }
}