some more problems

This commit is contained in:
Gleb Koval 2022-05-30 23:03:12 +01:00
parent e7b17e4450
commit 8181578c11
3 changed files with 69 additions and 0 deletions

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impl Solution {
pub fn max_profit(prices: Vec<i32>) -> i32 {
prices
.iter()
.fold((prices[0], 0), |(min, max_diff), &price| {
if price < min {
return (price, max_diff);
}
(min, max_diff.max(price - min))
}).1
}
}

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// Assume shift operators are allowed
impl Solution {
#[inline]
pub fn negative(n: i32) -> i32 {
if n.is_positive() {
return !(n - 1);
}
n
}
pub fn divide(dividend: i32, divisor: i32) -> i32 {
let positive = dividend ^ divisor >= 0;
let negative_divisor = Solution::negative(divisor);
let negative_answer = (0..negative_divisor.leading_ones()) // Preform all arithmetic in negative because of larger available range of numbers
.rev() // Reverse to get most extreme subdivisor first
.map(|n| negative_divisor << n) // Generate subdivisors
.fold((0, Solution::negative(dividend)), |(quotient, carry), subdivisor| {
if subdivisor >= carry {
return ((quotient << 1) - 1, carry - subdivisor);
}
return (quotient << 1, carry);
}).0;
if positive {
let answer = !negative_answer;
if answer != std::i32::MAX {
return answer + 1;
}
return answer;
}
negative_answer
}
}

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use std::collections::HashMap;
impl Solution {
pub fn intersect(nums1: Vec<i32>, nums2: Vec<i32>) -> Vec<i32> {
// Get longer & shorter side to optimise memory a little
let (longer, shorter) = if nums1.len() > nums2.len() {
(nums1.into_iter(), nums2.into_iter())
} else {
(nums2.into_iter(), nums1.into_iter())
};
// Get counts of each element of shorter vector
let mut counts: HashMap<i32, i32> = shorter
.fold(HashMap::new(), |mut counts, n| {
counts.insert(n, 1 + *counts.get(&n).unwrap_or(&0));
counts
});
// Filter longer vector using the counts of the elements of the shorter vector
longer
.filter(|n| {
let count = *counts.get(n).unwrap_or(&0);
counts.insert(*n, count - 1);
count.is_positive()
})
.collect()
}
}