diff options
Diffstat (limited to 'sum_dist_tree.rs')
-rw-r--r-- | sum_dist_tree.rs | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/sum_dist_tree.rs b/sum_dist_tree.rs new file mode 100644 index 0000000..d000d83 --- /dev/null +++ b/sum_dist_tree.rs @@ -0,0 +1,49 @@ +struct Solution; + +impl Solution { + pub fn sum_of_distances_in_tree(n: i32, edges: Vec<Vec<i32>>) -> Vec<i32> { + let n = n as usize; + let mut adj: Vec<Vec<usize>> = vec![Vec::new(); n]; + for e in edges.iter() { + adj[e[0] as usize].push(e[1] as usize); + adj[e[1] as usize].push(e[0] as usize); + } + let mut dp = vec![[0; 2]; n]; + Self::get_depth_sum_count(0, n, &mut dp, &adj); + let mut ans = vec![0; n]; + Self::get_ans(0, n, 0, &mut ans, &dp, &adj); + ans + } + fn get_depth_sum_count(i: usize, parent: usize, dp: &mut Vec<[i32; 2]>, adj: &Vec<Vec<usize>>) { + dp[i][1] = 1; + for &j in adj[i].iter() { + if j == parent { + continue; + } + Self::get_depth_sum_count(j, i, dp, adj); + dp[i][0] += dp[j][0] + dp[j][1]; + dp[i][1] += dp[j][1]; + } + } + fn get_ans(i: usize, parent: usize, acc_sum: i32, ans: &mut Vec<i32>, dp: &Vec<[i32; 2]>, adj: &Vec<Vec<usize>>) { + ans[i] = acc_sum + dp[i][0]; + for &j in adj[i].iter() { + if j == parent { + continue; + } + let sum2 = acc_sum + dp[i][0] + dp.len() as i32 - dp[j][0] - dp[j][1] * 2; + Self::get_ans(j, i, sum2, ans, dp, adj); + } + } +} + +fn main() { + let edges = vec![ + vec![0,1], + vec![0,2], + vec![2,3], + vec![2,4], + vec![2,5] + ]; + print!("{:?}", Solution::sum_of_distances_in_tree(6, edges)); +} |