72 lines
1.8 KiB
Rust
72 lines
1.8 KiB
Rust
/**
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* [887] Super Egg Drop
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*/
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pub struct Solution {}
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// submission codes start here
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use std::cmp::Ordering;
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use std::collections::HashMap;
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impl Solution {
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pub fn super_egg_drop(k: i32, n: i32) -> i32 {
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let mut map = HashMap::new();
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Self::dp(k, n, &mut map)
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}
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fn dp(k: i32, n: i32, memory: &mut HashMap<i32, i32>) -> i32 {
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if let Some(value) = memory.get(&(n * 100 + k)) {
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return *value;
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}
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let result = if n == 0 {
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0
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} else if k == 1 {
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n
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} else {
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let (mut left, mut right) = (1, n);
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while left + 1 < right {
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let middle = (left + right) / 2;
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let left_value = Self::dp(k - 1, middle - 1, memory);
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let right_value = Self::dp(k, n - middle, memory);
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match left_value.cmp(&right_value) {
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Ordering::Less => {
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left = middle;
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}
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Ordering::Equal => {
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left = middle;
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right = middle;
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}
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Ordering::Greater => {
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right = middle;
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}
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}
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}
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1 + Self::dp(k - 1, left - 1, memory)
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.max(Self::dp(k, n - left, memory))
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.min(Self::dp(k - 1, right - 1, memory).max(Self::dp(k, n - right, memory)))
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};
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memory.insert(n * 100 + k, result);
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result
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}
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}
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// submission codes end
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn test_887() {
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assert_eq!(2, Solution::super_egg_drop(1, 2));
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assert_eq!(3, Solution::super_egg_drop(2, 6));
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assert_eq!(4, Solution::super_egg_drop(3, 14));
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}
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}
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