thảo luận Leetcode mỗi ngày

use std::collections::*;
impl Solution {
    pub fn find_the_longest_substring(s: String) -> i32 {
        let (bytes, n) = (s.as_bytes(), s.len());

        let presence =
            0u32 | 1u32 << b'a' - b'a' | 1u32 << b'e' - b'a' | 1u32 <<  b'i' - b'a' | 1u32 << b'o' - b'a' | 1u32 << b'u' - b'a';

        let mut pref = vec![0u32; n];
        pref[0] = 1u32 << (bytes[0] - b'a');
        for i in 1..n {
            pref[i] = (pref[i - 1] ^ (1u32 << bytes[i] - b'a')) & presence;
        }

        let mut result = 0;
        let mut seen: HashMap<u32, usize> = HashMap::new();

        for right in 0..n {
            let bitset = pref[right];

            if bitset == 0 {
                result = result.max(right + 1);
            } else if let Some(&left) = seen.get(&bitset) {
                result = result.max(right - left);
            }

            seen.entry(bitset).or_insert(right);
        }

        result as i32
    }
}

use std::collections::*;

impl Solution {
    pub fn find_the_longest_substring(s: String) -> i32 {
        let (bytes, n) = (s.as_bytes(), s.len());

        let mut seen = vec![usize::MAX; 32];
        seen[0] = 0;

        let (mut bitset, mut result) = (0, 0);

        for (right, bc) in bytes.iter().copied().enumerate() {
             match bc {
                b'a' => bitset ^= 1,
                b'e' => bitset ^= 2,
                b'i' => bitset ^= 4,
                b'o' => bitset ^= 8,
                b'u' => bitset ^= 16,
                _ => ()
            }

            if bitset == 0 {
                result = result.max(right + 1);
            } else {
                let left = seen[bitset];

                if left != usize::MAX {
                    result = result.max(right + 1 - left);
                }
            }

            if seen[bitset] == usize::MAX {
                seen[bitset] = right + 1;
            }
        }

        result as i32
    }
}

class Solution:
    def findTheLongestSubstring(self, s: str) -> int:
        xorMap = {}
        xorMap[0] = -1
        countMap = [0] * 5
        res = 0
        for i in range(len(s)):
            if s[i]=='u':
                countMap[0] = 1- countMap[0]
            elif s[i]=='e':
                countMap[1] = 1- countMap[1]
            elif s[i]=='o':
                countMap[2] = 1- countMap[2]
            elif s[i]=='a':
                countMap[3] = 1- countMap[3]
            elif s[i]=='i':
                countMap[4] = 1- countMap[4]
            binary = ''.join(str(x) for x in countMap)
            decimal = int(binary,2)
            if decimal in xorMap:
                res = max(res,i-xorMap[decimal])
            else:
                xorMap[decimal] = i
        return res

public class Solution
{
    public int FindTheLongestSubstring(string s)
    {
        Dictionary<char, int> map = new(5);
        map['a'] = 0; map['e'] = 1; map['i'] = 2; map['o'] = 3; map['u'] = 4;
        
        int[] prefix = new int[s.Length + 1];
        for (int i = 1; i <= s.Length; i++)
        {
            int value = !IsVowel(s[i - 1]) ? 0 : 1 << map[s[i - 1]];
            prefix[i] = prefix[i - 1] ^ value;
        }
        
        int result = 0;
        Dictionary<int, int> dict = new();
        for (int i = 0; i < prefix.Length; i++)
        {
            if (!dict.ContainsKey(prefix[i]))
            {
                dict[prefix[i]] = i;
                continue;
            }
            result = Math.Max(i - dict[prefix[i]], result);
        }
        
        return result;
    }
    private bool IsVowel(char c)
    {
        return c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u';
    }
}