161. One Edit Distance

https://leetcode.com/problems/one-edit-distance

• CTCI 1.5 One Away

Python

class Solution:
    def isOneEditDistance(self, s: str, t: str) -> bool:
        if s == t:
            return False
        elif len(s) == len(t):
            return self.one_edit_replace(s, t)
        elif len(s)+1 == len(t):
            return self.one_edit_insert(s, t)
        elif len(s)-1 == len(t):
            return self.one_edit_insert(t, s)

        return False

    def one_edit_insert(self, s1, s2) -> bool:
        cur1, cur2 = 0, 0
        while cur1 < len(s1) and cur2 < len(s2):
            if s1[cur1] != s2[cur2]:
                if cur1 != cur2:
                    return False
                cur2 += 1
            else:
                cur1 += 1
                cur2 += 1
        return True

    def one_edit_replace(self, s1, s2) -> bool:
        see_diff = False
        for i in range(len(s1)):
            if s1[i] != s2[i]:
                if see_diff:
                    return False
                see_diff = True
        return True

Rust

impl Solution {
    pub fn is_one_edit_distance(s: String, t: String) -> bool {
        if s == t {
            return false;
        } else if s.len() == t.len() {
            return Solution::one_edit_replace(s, t);
        } else if s.len()+1 == t.len() {
            return Solution::one_edit_insert(s, t);
        } else if s.len()-1 == t.len() {
            return Solution::one_edit_insert(t, s);
        }

        false
    }

    pub fn one_edit_insert(s1: String, s2: String) -> bool {
        let mut cur1: usize = 0;
        let mut cur2: usize = 0;

        while cur1 < s1.len() && cur2 < s2.len() {
            if s1.chars().nth(cur1) != s2.chars().nth(cur2) {
                if cur1 != cur2 {
                    return false;
                }
                cur2 += 1;
            } else {
                cur1 += 1;
                cur2 += 1;
            }
        }
        true
    }

    pub fn one_edit_replace(s1: String, s2: String) -> bool {
        let mut see_diff = false;
        for i in 0..s1.len() {
            if s1.chars().nth(i) != s2.chars().nth(i) {
                if see_diff {
                    return false;
                }
                see_diff = true;
            }
        }
        true
    }
}