leetcode/src/problem/p1128_number_of_equivalent_domino_pairs.rs
2025-05-04 14:59:51 +08:00

59 lines
1.3 KiB
Rust

/**
* [1128] Number of Equivalent Domino Pairs
*/
pub struct Solution {}
// submission codes start here
use std::collections::HashMap;
impl Solution {
pub fn num_equiv_domino_pairs(dominoes: Vec<Vec<i32>>) -> i32 {
let mut map = HashMap::new();
let mut result = 0;
for card in dominoes.iter() {
let sum = card[0] * 10 + card[1];
if let Some(count) = map.get(&sum) {
result += *count;
}
let entry = map.entry(sum).or_insert(0);
*entry += 1;
let reverse_sum = card[1] * 10 + card[0];
if reverse_sum != sum {
let entry = map.entry(card[1] * 10 + card[0]).or_insert(0);
*entry += 1;
}
}
result
}
}
// submission codes end
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_1128() {
assert_eq!(
1,
Solution::num_equiv_domino_pairs(vec![vec![1, 2], vec![2, 1], vec![3, 4], vec![5, 6]])
);
assert_eq!(
3,
Solution::num_equiv_domino_pairs(vec![
vec![1, 2],
vec![1, 2],
vec![1, 1],
vec![1, 2],
vec![2, 2]
])
);
}
}