93 lines
1.7 KiB
Rust
93 lines
1.7 KiB
Rust
/**
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* [149] Max Points on a Line
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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::collections::HashMap;
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#[derive(Ord, PartialOrd, Eq, PartialEq, Hash)]
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struct Slope {
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x: i32,
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y: i32,
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}
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impl Slope {
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fn new(point1: &Vec<i32>, point2: &Vec<i32>) -> Self {
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let mut x = point1[0] - point2[0];
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let mut y = point1[1] - point2[1];
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if x == 0 {
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y = 1;
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} else if y == 0 {
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x = 1;
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} else {
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if y < 0 {
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x = -x;
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y = -y;
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}
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let gcd = Self::gcd(x.abs(), y.abs());
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x /= gcd;
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y /= gcd;
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}
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Self {
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x,
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y,
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}
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}
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fn gcd(a: i32, b: i32) -> i32 {
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if b > 0 {
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Self::gcd(b, a % b)
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} else {
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a
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}
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}
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}
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impl Solution {
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pub fn max_points(points: Vec<Vec<i32>>) -> i32 {
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let n = points.len();
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if n <= 2 {
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return n as i32;
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}
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let mut result = 0;
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for i in 0..n {
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if result > n - i || result > n / 2 {
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break;
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}
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let mut map = HashMap::new();
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for j in i+1..n {
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let slope = Slope::new(&points[i], &points[j]);
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let entry = map.entry(slope).or_insert(0);
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*entry += 1;
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}
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let mut max = 0;
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for i in map.values() {
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max = max.max(*i);
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}
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result = result.max(max + 1);
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}
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result as i32
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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_149() {}
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}
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