From d4132e91d4e6744d89690aad495fd718c7e16d2b Mon Sep 17 00:00:00 2001 From: jackfiled Date: Fri, 5 Jan 2024 19:41:11 +0800 Subject: [PATCH] 20240105 Finished --- src/solution/mod.rs | 1 + src/solution/s0743_network_delay_time.rs | 129 +++++++++++++++++++++++ 2 files changed, 130 insertions(+) create mode 100644 src/solution/s0743_network_delay_time.rs diff --git a/src/solution/mod.rs b/src/solution/mod.rs index 27280b2..2452bc2 100644 --- a/src/solution/mod.rs +++ b/src/solution/mod.rs @@ -12,3 +12,4 @@ mod s1276_number_of_burgers_with_no_waste_of_ingredients; mod s0006_zigzag_conversion; mod s0007_reverse_integer; mod s0004_median_of_two_sorted_arrays; +mod s0743_network_delay_time; diff --git a/src/solution/s0743_network_delay_time.rs b/src/solution/s0743_network_delay_time.rs new file mode 100644 index 0000000..910144f --- /dev/null +++ b/src/solution/s0743_network_delay_time.rs @@ -0,0 +1,129 @@ +/** + * [743] Network Delay Time + * + * You are given a network of n nodes, labeled from 1 to n. You are also given times, a list of travel times as directed edges times[i] = (ui, vi, wi), where ui is the source node, vi is the target node, and wi is the time it takes for a signal to travel from source to target. + * We will send a signal from a given node k. Return the minimum time it takes for all the n nodes to receive the signal. If it is impossible for all the n nodes to receive the signal, return -1. + * + * Example 1: + * + * Input: times = [[2,1,1],[2,3,1],[3,4,1]], n = 4, k = 2 + * Output: 2 + * + * Example 2: + * + * Input: times = [[1,2,1]], n = 2, k = 1 + * Output: 1 + * + * Example 3: + * + * Input: times = [[1,2,1]], n = 2, k = 2 + * Output: -1 + * + * + * Constraints: + * + * 1 <= k <= n <= 100 + * 1 <= times.length <= 6000 + * times[i].length == 3 + * 1 <= ui, vi <= n + * ui != vi + * 0 <= wi <= 100 + * All the pairs (ui, vi) are unique. (i.e., no multiple edges.) + * + */ +pub struct Solution {} + +// problem: https://leetcode.cn/problems/network-delay-time/ +// discuss: https://leetcode.cn/problems/network-delay-time/discuss/?currentPage=1&orderBy=most_votes&query= + +// submission codes start here + +use std::cmp::{max, min}; +use std::collections::HashSet; + +impl Solution { + pub fn network_delay_time(times: Vec>, n: i32, k: i32) -> i32 { + let n = n as usize; + let k = k as usize; + + let mut matrix = Vec::with_capacity(n + 1); + + for _i in 0..=n { + let mut line = Vec::with_capacity(n + 1); + line.resize(n + 1, i32::MAX); + matrix.push(line); + } + + for line in × { + matrix[line[0] as usize][line[1] as usize] = line[2]; + } + + let mut path = HashSet::with_capacity(n + 1); + path.insert(k); + let mut distances = matrix[k].clone(); + + for _ in 2..=n { + let (mut index, mut value) = (0usize, i32::MAX); + + for (i, d) in distances.iter().enumerate() { + if path.contains(&i) { + continue; + } + + if value > *d { + value = *d; + index = i; + } + } + + if value == i32::MAX { + break; + } + + path.insert(index); + + for i in 1..=n { + if path.contains(&i) { + continue; + } + + if matrix[index][i] == i32::MAX { + continue; + } + + distances[i] = min(distances[i], value + matrix[index][i]); + } + } + + let mut result = i32::MIN; + + for i in 1..distances.len() { + if i == k { + continue + } + + result = max(result, distances[i]); + } + + return if result == i32::MAX { + -1 + } else { + result + } + } +} + +// submission codes end + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn test_743() { + assert_eq!(Solution::network_delay_time( + vec![vec![2,1,1], vec![2,3,1], vec![3,4,1]], 4, 2), 2); + assert_eq!(Solution::network_delay_time(vec![vec![1,2,1]], 2, 1), 1); + assert_eq!(Solution::network_delay_time(vec![vec![1,2,1]], 2, 2), -1); + } +}