I am solving LeetCode Dynamic Programming challenges (this one is #72, at https://leetcode.com/problems/editdistance).
Here below, I’ve implemented a Rust solution for the minimum edit distance between two strings problem
use std::collections::HashMap;
use std::cmp::min;
impl Solution {
pub fn min_distance(word1: String, word2: String) > i32 {
let mut D: HashMap<(i32, i32), i32> = HashMap::new();
let m = word1.len() as i32;
let n = word2.len() as i32;
let w1: Vec<char> = word1.chars().collect();
let w2: Vec<char> = word2.chars().collect();
for i in 0..=m {
D.insert((i, 0), i);
}
for j in 0..=n {
D.insert((0, j), j);
}
for i in 1..=m {
for j in 1..=n {
if w1((i1) as usize) == w2((j1) as usize) {
D.insert((i, j), *D.get(&(i1, j1)).unwrap());
} else {
let p = *D.get(&(i  1, j  1)).unwrap();
let q = *D.get(&(i  1, j)).unwrap();
let r = *D.get(&(i, j  1)).unwrap();
D.insert((i, j), 1 + min(p, min(q, r)));
}
}
}
return *D.get(&(m, n)).unwrap();
}
}
I’ve actually also solved the same thing in JAVA, which I have a much better command on…
public class EditDistance {
public static int minDistance(String word1, String word2) {
int m = word1.length();
int n = word2.length();
int()() D = new int(m+1)(n+1);
for(int i=0; i<=m; ++i) D(i)(0) = i;
for(int j=0; j<=n; ++j) D(0)(j) = j;
for(int i=1; i<=m; ++i) {
for(int j=1; j<=n; ++j) {
if(word1.charAt(i1) == word2.charAt(j1)) D(i)(j) = D(i1)(j1);
else D(i)(j) = 1 + Math.min(D(i1)(j1), Math.min(D(i1)(j), D(i)(j1)));
}
}
return D(m)(n);
}
public static void main(String() args) {
System.out.println(minDistance("intention", "execution"));
}
}
Something about my Rust solution seems off to me. Not really sure but here are some of my irritations:

I couldn’t find a better way to iterate a string and refer to it by its index easily other than having to convert it to a vector.

I think I’m
unwrap()
ing too much. Although I’m not aiming for code golf here, it still feels subconsciously that I could have avoided so manyunwrap()
s. 
I feel a bit bad because I kind of word to word translated my solution from Java… perhaps there’s a more Rustidiomatic way of doing whatever I did?
Looking forward to your advise and help ðŸ™‚ Thanks in advance!