# ZigZag Conversion in C++

C++Server Side ProgrammingProgramming

Suppose the string is like " IWANTTOLEARNCODE". This string is written in a zigzag way on a given number of rows say n. So the pattern is looking like this

 I T A O W N O E R C D A L N E

When we read the line like − "ITAOWNOERCDALNE"

So we have to create one module that can perform this kind of operation by taking the string and the number of rows.

To solve this, we will follow these steps

• when n = 1, then return s
• create an array of strings arr of size n
• row := 0, and down := true
• for i in range 0 to size of string – 1
• insert s[i] at the end of string arr[row]
• if row = b – 1, then down := false, otherwise when row= 0, then down := true
• if down is true, then increase row by 1, otherwise decrease row by 1
• ans := blank string
• for i in range 0 to n – 1:
• ans := ans + arr[i]
• return ans

## Example(C++)

Let us see the following implementation to get a better understanding −

Live Demo

#include <bits/stdc++.h>
using namespace std;
class Solution {
public:
string convert(string s, int numRows);
};
string Solution::convert(string a, int b) {
if(b == 1)return a;
string arr[b];
int row = 0;
bool down = true;
for(int i = 0; i < a.size(); i++){
arr[row].push_back(a[i]);
if(row == b - 1) down = false;
else if(row == 0)down = true;
if(down) row++;
else row--;
}
string ans = "";
for(int i = 0; i < b; i++){
ans += arr[i];
}
return ans;
}
main(){
Solution ob;
cout << ob.convert("IWANTTOLEARNCODE", 3);
}

## Input

"IWANTTOLEARNCODE"
3

## Output

"ITECWNTLANOEAORD"
Published on 30-Jan-2020 07:05:28