6. ZigZag Conversion

Stanislav Gumeniuk included in Leetcode Leetcode-Problem

2020-05-31 170 words One minute

Contents

Problem

The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)

P   A   H   N
A P L S I I G
Y   I   R

And then read line by line: "PAHNAPLSIIGYIR"

Write the code that will take a string and make this conversion given a number of rows:

string convert(string s, int numRows);

example 1

Input: s = "PAYPALISHIRING", numRows = 3
Output: "PAHNAPLSIIGYIR"

example 2

Input: s = "PAYPALISHIRING", numRows = 4
Output: "PINALSIGYAHRPI"
Explanation:

P     I    N
A   L S  I G
Y A   H R
P     I

Solution

Sort by Row

func convert(s string, numRows int) string {
    if numRows == 1 {
        return s        
    }
    a:= make(map[int]string, numRows)
    
    i:=0
    d:=+1
    for idx:=range s {
        if i == 0 {
            d=1
        }
        if i == numRows-1 {
            d=-1
        }
        a[i] += string(s[idx]) 
        
        i+=d
    }

    res := ""
    for idx:=0;idx<numRows;idx++{
        res +=a[idx]
    }
    return res
}