Problem:
Score : 200 points

Problem Statement

Given are two strings S and T.

Let us change some of the characters in S so that T will be a substring of S.

At least how many characters do we need to change?

Here, a substring is a consecutive subsequence. For example, xxx is a substring of yxxxy, but not a substring of xxyxx.

Constraints

The lengths of S and T are each at least 1 and at most 1000.

The length of T is at most that of S.

S and T consist of lowercase English letters.

Input

Input is given from Standard Input in the following format:

S
T

Output

Print the minimum number of characters in S that need to be changed.

Sample Input 1

cabacc
abc

Sample Output 1

1

For example, changing the fourth character a in S to c will match the second through fourth characters in S to T.

Since S itself does not have T as its substring, this number of changes - one - is the minimum needed.

Sample Input 2

codeforces
atcoder

Sample Output 2

6

Solution in Rust (1.42.0) (judge verdict: Accepted)

use proconio::{fastout, input};

#[fastout]
fn main() {
    input! {
        // s >= t
        s: String,
        t: String,
    };
    let diff = substr_diff(&s.as_bytes(), &t.as_bytes()).unwrap();
    println!("{}", diff);
}

fn diff_chars(t: &[u8], p: &[u8]) -> usize {
    fn rec(t:&[u8], p: &[u8], index: usize, count: usize) -> usize {
        if index >= p.len() {
            count
        } else {
            match t[index] == p[index] {
                true => {
                    rec(t, p, index + 1, count)
                }
                false => {
                    rec(t, p, index + 1, count + 1)
                }
            }
        }
    }
    rec(t, p, 0, 0)
}

fn substr_diff(text: &[u8], ptrn: &[u8]) -> Option<usize> {
    if text.len() < ptrn.len() {
        None
    } else {
        let tl = text.len();
        let pl = ptrn.len();
        let mut diff = pl;
        for i in 0..tl - pl + 1 {
            let substr = &text[i..i + pl];
            let temp = diff_chars(substr, &ptrn[..]);
            if temp < diff {
                diff = temp;
            };
        }
        Some(diff)
    }
}