README_EN.md

791. Custom Sort String

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Description

You are given two strings order and s. All the characters of order are unique and were sorted in some custom order previously.

Permute the characters of s so that they match the order that order was sorted. More specifically, if a character x occurs before a character y in order, then x should occur before y in the permuted string.

Return any permutation of s that satisfies this property.

 

Example 1:

Input: order = "cba", s = "abcd"
Output: "cbad"
Explanation: 
"a", "b", "c" appear in order, so the order of "a", "b", "c" should be "c", "b", and "a". 
Since "d" does not appear in order, it can be at any position in the returned string. "dcba", "cdba", "cbda" are also valid outputs.

Example 2:

Input: order = "cbafg", s = "abcd"
Output: "cbad"

 

Constraints:

• 1 <= order.length <= 26
• 1 <= s.length <= 200
• order and s consist of lowercase English letters.
• All the characters of order are unique.

Solutions

Python3

class Solution:
    def customSortString(self, order: str, s: str) -> str:
        d = {c: i for i, c in enumerate(order)}
        return ''.join(sorted(s, key=lambda x: d.get(x, 0)))

class Solution:
    def customSortString(self, order: str, s: str) -> str:
        cnt = Counter(s)
        ans = []
        for c in order:
            ans.append(c * cnt[c])
            cnt[c] = 0
        for c, v in cnt.items():
            ans.append(c * v)
        return ''.join(ans)

Java

class Solution {
    public String customSortString(String order, String s) {
        int[] d = new int[26];
        for (int i = 0; i < order.length(); ++i) {
            d[order.charAt(i) - 'a'] = i;
        }
        List<Character> cs = new ArrayList<>();
        for (int i = 0; i < s.length(); ++i) {
            cs.add(s.charAt(i));
        }
        cs.sort((a, b) -> d[a - 'a'] - d[b - 'a']);
        return cs.stream().map(String::valueOf).collect(Collectors.joining());
    }
}

class Solution {
    public String customSortString(String order, String s) {
        int[] cnt = new int[26];
        for (int i = 0; i < s.length(); ++i) {
            ++cnt[s.charAt(i) - 'a'];
        }
        StringBuilder ans = new StringBuilder();
        for (int i = 0; i < order.length(); ++i) {
            char c = order.charAt(i);
            while (cnt[c - 'a']-- > 0) {
                ans.append(c);
            }
        }
        for (int i = 0; i < 26; ++i) {
            while (cnt[i]-- > 0) {
                ans.append((char) ('a' + i));
            }
        }
        return ans.toString();
    }
}

C++

class Solution {
public:
    string customSortString(string order, string s) {
        int d[26] = {0};
        for (int i = 0; i < order.size(); ++i) d[order[i] - 'a'] = i;
        sort(s.begin(), s.end(), [&](auto a, auto b) { return d[a - 'a'] < d[b - 'a']; });
        return s;
    }
};

class Solution {
public:
    string customSortString(string order, string s) {
        int cnt[26] = {0};
        for (char& c : s) ++cnt[c - 'a'];
        string ans;
        for (char& c : order)
            while (cnt[c - 'a']-- > 0) ans += c;
        for (int i = 0; i < 26; ++i)
            if (cnt[i] > 0) ans += string(cnt[i], i + 'a');
        return ans;
    }
};

Go

func customSortString(order string, s string) string {
	d := [26]int{}
	for i := range order {
		d[order[i]-'a'] = i
	}
	cs := []byte(s)
	sort.Slice(cs, func(i, j int) bool { return d[cs[i]-'a'] < d[cs[j]-'a'] })
	return string(cs)
}

func customSortString(order string, s string) string {
	cnt := [26]int{}
	for _, c := range s {
		cnt[c-'a']++
	}
	ans := []rune{}
	for _, c := range order {
		for cnt[c-'a'] > 0 {
			ans = append(ans, c)
			cnt[c-'a']--
		}
	}
	for i, v := range cnt {
		for j := 0; j < v; j++ {
			ans = append(ans, rune('a'+i))
		}
	}
	return string(ans)
}

TypeScript

function customSortString(order: string, s: string): string {
    const toIndex = (c: string) => c.charCodeAt(0) - 'a'.charCodeAt(0);
    const n = order.length;
    const d = new Array(26).fill(n);
    for (let i = 0; i < n; i++) {
        d[toIndex(order[i])] = i;
    }
    return [...s].sort((a, b) => d[toIndex(a)] - d[toIndex(b)]).join('');
}

function customSortString(order: string, s: string): string {
    const toIndex = (c: string) => c.charCodeAt(0) - 'a'.charCodeAt(0);
    const count = new Array(26).fill(0);
    for (const c of s) {
        count[toIndex(c)]++;
    }
    const ans: string[] = [];
    for (const c of order) {
        const i = toIndex(c);
        ans.push(c.repeat(count[i]));
        count[i] = 0;
    }
    for (let i = 0; i < 26; i++) {
        if (!count[i]) continue;
        ans.push(String.fromCharCode('a'.charCodeAt(0) + i).repeat(count[i]));
    }
    return ans.join('');
}

Rust

impl Solution {
    pub fn custom_sort_string(order: String, s: String) -> String {
        let n = order.len();
        let mut d = [n; 26];
        for (i, c) in order.as_bytes().iter().enumerate() {
            d[(c - b'a') as usize] = i;
        }
        let mut ans = s.chars().collect::<Vec<_>>();
        ans.sort_by(|&a, &b|
            d[((a as u8) - ('a' as u8)) as usize].cmp(&d[((b as u8) - ('a' as u8)) as usize])
        );
        ans.into_iter().collect()
    }
}

impl Solution {
    pub fn custom_sort_string(order: String, s: String) -> String {
        let mut count = [0; 26];
        for c in s.as_bytes() {
            count[(c - b'a') as usize] += 1;
        }
        let mut ans = String::new();
        for c in order.as_bytes() {
            for _ in 0..count[(c - b'a') as usize] {
                ans.push(char::from(*c));
            }
            count[(c - b'a') as usize] = 0;
        }
        for i in 0..count.len() {
            for _ in 0..count[i] {
                ans.push(char::from(b'a' + (i as u8)));
            }
        }
        ans
    }
}

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