1768 Merge Strings Alternately 1

Joel Castillo Espinosa 2

DESCRIPTION

You are given two strings word1 and word2. Merge the strings by adding letters in alternating order, starting with word1. If a string is longer than the other, append the additional letters onto the end of the merged string.

Return the merged string.

Examples

  • Example 1:
    • Input: word1 = “abc”, word2 = “pqr”
    • Output: “apbqcr”
    • Explanation: The merged string will be merged as so:
      • word1: a _ b _ c _
      • word2: _ p _ q _ r
      • merged: a p b q c r
  • Example 2:
    • Input: word1 = “ab”, word2 = “pqrs”
    • Output: “apbqrs”
    • Explanation: Notice that as word2 is longer, “rs” is appended to the end.
      • word1: a _ b _
      • word2: _ p _ q r s
      • merged: a p b q r s
  • Example 3:
    • Input: word1 = “abcd”, word2 = “pq”
    • Output: “apbqcd”
    • Explanation: Notice that as word1 is longer, “cd” is appended to the end.
      • word1: a _ b _ c d
      • word2: _ p _ q _
      • merged: a p b q c d

Constraints:

  • 1 ≤ word1.length, word2.length ≤ 100
  • word1 and word2 consist of lowercase English letters

SOLUTION 3

merg_str <- function(word1, word2){
  # split the words in letters
  split1 <-strsplit(word1,"")
  split2 <-strsplit(word2,"") 
  l_w1 <- length(split1[[1]])
  l_w2 <- length(split2[[1]])
  
  string <- "" # element that contains the merge
  
  # in each iteration, take an element (letter or "") per word 
  for (i in 1:max(l_w1,l_w2)) { # to include all elements 
    if (is.na(split1[[1]][i])) {letter1 <- ""} 
    else{ letter1 <-split1[[1]][i] }
    
    if (is.na(split2[[1]][i])) {letter2 <- ""}
    else { letter2 <- split2[[1]][i] }
    
    string <- paste(string,letter1,letter2, sep = "") 
  }
  return(string)
}

Examples using the function

We can use the examples presented before.

merg_str("abc","pqr")

## [1] "apbqcr"

merg_str(word1 = "ab", word2 = "pqrs")

## [1] "apbqrs"

merg_str(word1 = "abcd", word2 = "pq")

## [1] "apbqcd"

  1. This problem is originally from LeetCode, you can find it in Leetcode. ↩

  2. Email: jocastillo@colmex.mx. For more content visit my website: https://joelcastillo.netlify.app
    If you have any questions or suggestions, I’d be grateful to hear from you. ↩

  3. This solution is entirely my own work. It was developed using R version 4.4.1 (2024-06-14 ucrt). ↩