1790-CheckIfOneStringSwapCanMakeStringsEqual.go

package main

// 1790. Check if One String Swap Can Make Strings Equal
// You are given two strings s1 and s2 of equal length. 
// A string swap is an operation where you choose two indices in a string (not necessarily different) 
// and swap the characters at these indices.

// Return true if it is possible to make both strings equal 
// by performing at most one string swap on exactly one of the strings. 
// Otherwise, return false.

// Example 1:
// Input: s1 = "bank", s2 = "kanb"
// Output: true
// Explanation: For example, swap the first character with the last character of s2 to make "bank".

// Example 2:
// Input: s1 = "attack", s2 = "defend"
// Output: false
// Explanation: It is impossible to make them equal with one string swap.

// Example 3:
// Input: s1 = "kelb", s2 = "kelb"
// Output: true
// Explanation: The two strings are already equal, so no string swap operation is required.

// Constraints:
//     1 <= s1.length, s2.length <= 100
//     s1.length == s2.length
//     s1 and s2 consist of only lowercase English letters.

import "fmt"

func areAlmostEqual(s1 string, s2 string) bool {
    count, mp := 0, make([]int, 26)
    for i := range s1 {
        if s1[i] != s2[i] { count++ }
        if count > 2 { return false }
        mp[s1[i] - 'a']++
        mp[s2[i] - 'a']--
    }
    for _, v := range mp { 
        if v != 0 { return false } 
    }
    return true
}

func main() {
    // Example 1:
    // Input: s1 = "bank", s2 = "kanb"
    // Output: true
    // Explanation: For example, swap the first character with the last character of s2 to make "bank".
    fmt.Println(areAlmostEqual("bank", "kanb")) // true
    // Example 2:
    // Input: s1 = "attack", s2 = "defend"
    // Output: false
    // Explanation: It is impossible to make them equal with one string swap.
    fmt.Println(areAlmostEqual("attack", "defend")) // false
    // Example 3:
    // Input: s1 = "kelb", s2 = "kelb"
    // Output: true
    // Explanation: The two strings are already equal, so no string swap operation is required.
    fmt.Println(areAlmostEqual("kelb", "kelb")) // true
}