Given a list of words
, list of single letters
(might be repeating) and score
of every character.
Return the maximum score of any valid set of words formed by using the given letters (words[i]
cannot be used two or more times).
It is not necessary to use all characters in letters
and each letter can only be used once. Score of letters 'a'
, 'b'
, 'c'
, ... ,'z'
is given by score[0]
, score[1]
, ... , score[25]
respectively.
Example 1:
Input: words = ["dog","cat","dad","good"], letters = ["a","a","c","d","d","d","g","o","o"], score = [1,0,9,5,0,0,3,0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0] Output: 23 Explanation: Score a=1, c=9, d=5, g=3, o=2 Given letters, we can form the words "dad" (5+1+5) and "good" (3+2+2+5) with a score of 23. Words "dad" and "dog" only get a score of 21.
Example 2:
Input: words = ["xxxz","ax","bx","cx"], letters = ["z","a","b","c","x","x","x"], score = [4,4,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,5,0,10] Output: 27 Explanation: Score a=4, b=4, c=4, x=5, z=10 Given letters, we can form the words "ax" (4+5), "bx" (4+5) and "cx" (4+5) with a score of 27. Word "xxxz" only get a score of 25.
Example 3:
Input: words = ["leetcode"], letters = ["l","e","t","c","o","d"], score = [0,0,1,1,1,0,0,0,0,0,0,1,0,0,1,0,0,0,0,1,0,0,0,0,0,0] Output: 0 Explanation: Letter "e" can only be used once.
Constraints:
1 <= words.length <= 14
1 <= words[i].length <= 15
1 <= letters.length <= 100
letters[i].length == 1
score.length == 26
0 <= score[i] <= 10
words[i]
, letters[i]
contains only lower case English letters.struct Solution;
impl Solution {
fn max_score_words(words: Vec<String>, letters: Vec<char>, score: Vec<i32>) -> i32 {
let mut count: Vec<i32> = vec![0; 26];
for c in letters {
count[(c as u8 - b'a') as usize] += 1;
}
let n = words.len();
let scores: Vec<i32> = words
.iter()
.map(|s| s.bytes().map(|b| score[(b - b'a') as usize]).sum())
.collect();
let mut res = 0;
Self::dfs(0, 0, &mut count, &mut res, &words, &scores, n);
res
}
fn dfs(
start: usize,
sum: i32,
count: &mut Vec<i32>,
max: &mut i32,
words: &[String],
scores: &[i32],
n: usize,
) {
if start == n {
*max = (*max).max(sum);
} else {
Self::dfs(start + 1, sum, count, max, words, scores, n);
Self::update(count, &words[start], -1);
if Self::check(count, &words[start]) {
Self::dfs(start + 1, sum + scores[start], count, max, words, scores, n);
}
Self::update(count, &words[start], 1);
}
}
fn update(count: &mut Vec<i32>, s: &str, val: i32) {
for c in s.chars() {
count[(c as u8 - b'a') as usize] += val;
}
}
fn check(count: &mut Vec<i32>, s: &str) -> bool {
for c in s.chars() {
if count[(c as u8 - b'a') as usize] < 0 {
return false;
}
}
true
}
}
#[test]
fn test() {
let words = vec_string!["dog", "cat", "dad", "good"];
let letters = vec!['a', 'a', 'c', 'd', 'd', 'd', 'g', 'o', 'o'];
let score = vec![
1, 0, 9, 5, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
];
let res = 23;
assert_eq!(Solution::max_score_words(words, letters, score), res);
let words = vec_string!["xxxz", "ax", "bx", "cx"];
let letters = vec!['z', 'a', 'b', 'c', 'x', 'x', 'x'];
let score = vec![
4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 10,
];
let res = 27;
assert_eq!(Solution::max_score_words(words, letters, score), res);
let words = vec_string!["leetcode"];
let letters = vec!['l', 'e', 't', 'c', 'o', 'd'];
let score = vec![
0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0,
];
let res = 0;
assert_eq!(Solution::max_score_words(words, letters, score), res);
}