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Commit 5524223

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Solve #241
1 parent 40c3668 commit 5524223

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3 files changed

+106
-18
lines changed

3 files changed

+106
-18
lines changed

‎src/lib.rs‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -203,3 +203,4 @@ mod n0232_implement_queue_using_stacks;
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mod n0233_number_of_digit_one;
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mod n0238_product_of_array_except_self;
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mod n0239_sliding_window_maximum;
206+
mod n0241_different_ways_to_add_parentheses;

‎src/n0106_construct_binary_tree_from_inorder_and_postorder_traversal.rs‎

Lines changed: 32 additions & 18 deletions
Original file line numberDiff line numberDiff line change
@@ -2,46 +2,54 @@
22
* [106] Construct Binary Tree from Inorder and Postorder Traversal
33
*
44
* Given inorder and postorder traversal of a tree, construct the binary tree.
5-
*
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*
66
* Note:<br />
77
* You may assume that duplicates do not exist in the tree.
8-
*
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*
99
* For example, given
10-
*
11-
*
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*
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*
1212
* inorder = [9,3,15,20,7]
1313
* postorder = [9,15,7,20,3]
14-
*
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*
1515
* Return the following binary tree:
16-
*
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*
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*
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*
1818
* 3
1919
* / \
2020
* 9 20
2121
* / \
2222
* 15 7
23-
*
24-
*
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*
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*
2525
*/
2626
pub struct Solution {}
27-
use super::util::tree::{TreeNode, to_tree};
27+
use super::util::tree::{to_tree,TreeNode};
2828

2929
// submission codes start here
3030

31-
use std::rc::Rc;
3231
use std::cell::RefCell;
32+
use std::rc::Rc;
3333
impl Solution {
3434
pub fn build_tree(inorder: Vec<i32>, postorder: Vec<i32>) -> Option<Rc<RefCell<TreeNode>>> {
35-
Solution::build_tree_helper(&postorder[..], &inorder[..],)
35+
Solution::build_tree_helper(&postorder[..], &inorder[..])
3636
}
3737

3838
fn build_tree_helper(postorder: &[i32], inorder: &[i32]) -> Option<Rc<RefCell<TreeNode>>> {
39-
if postorder.is_empty() { return None }
40-
let root_idx = inorder.iter().position(|v| v == postorder.last().unwrap()).unwrap();
41-
Some(Rc::new(RefCell::new(TreeNode{
39+
if postorder.is_empty() {
40+
return None;
41+
}
42+
let root_idx = inorder
43+
.iter()
44+
.position(|v| v == postorder.last().unwrap())
45+
.unwrap();
46+
Some(Rc::new(RefCell::new(TreeNode {
4247
val: *postorder.last().unwrap(),
4348
left: Solution::build_tree_helper(&postorder[0..root_idx], &inorder[0..root_idx]),
44-
right: Solution::build_tree_helper(&postorder[root_idx..postorder.len()-1], &inorder[root_idx+1..]),
49+
right: Solution::build_tree_helper(
50+
&postorder[root_idx..postorder.len() - 1],
51+
&inorder[root_idx + 1..],
52+
),
4553
})))
4654
}
4755
}
@@ -54,8 +62,14 @@ mod tests {
5462

5563
#[test]
5664
fn test_106() {
57-
assert_eq!(Solution::build_tree(vec![9,3,15,20,7], vec![9,15,7,20,3]), tree![3,9,20,null,null,15,7]);
58-
assert_eq!(Solution::build_tree(vec![3,20,7], vec![7,20,3]), tree![3,null,20,null,7]);
65+
assert_eq!(
66+
Solution::build_tree(vec![9, 3, 15, 20, 7], vec![9, 15, 7, 20, 3]),
67+
tree![3, 9, 20, null, null, 15, 7]
68+
);
69+
assert_eq!(
70+
Solution::build_tree(vec![3, 20, 7], vec![7, 20, 3]),
71+
tree![3, null, 20, null, 7]
72+
);
5973
assert_eq!(Solution::build_tree(vec![], vec![]), tree![]);
6074
}
6175
}
Lines changed: 73 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,73 @@
1+
/**
2+
* [241] Different Ways to Add Parentheses
3+
*
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* Given a string of numbers and operators, return all possible results from computing all the different possible ways to group numbers and operators. The valid operators are +, - and *.
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*
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* Example 1:
7+
*
8+
*
9+
* Input: "2-1-1"
10+
* Output: [0, 2]
11+
* Explanation:
12+
* ((2-1)-1) = 0
13+
* (2-(1-1)) = 2
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*
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* Example 2:
16+
*
17+
*
18+
* Input: "2*3-4*5"
19+
* Output: [-34, -14, -10, -10, 10]
20+
* Explanation:
21+
* (2*(3-(4*5))) = -34
22+
* ((2*3)-(4*5)) = -14
23+
* ((2*(3-4))*5) = -10
24+
* (2*((3-4)*5)) = -10
25+
* (((2*3)-4)*5) = 10
26+
*
27+
*/
28+
pub struct Solution {}
29+
30+
// submission codes start here
31+
32+
impl Solution {
33+
pub fn diff_ways_to_compute(input: String) -> Vec<i32> {
34+
Solution::helper(&input)
35+
}
36+
37+
pub fn helper(input: &str) -> Vec<i32> {
38+
if input.is_empty() { return vec![] }
39+
if let Ok(digit) = input.parse::<i32>() {
40+
return vec![digit]
41+
}
42+
let mut res: Vec<i32> = Vec::new();
43+
for (i, ch) in input.chars().enumerate() {
44+
if ch == '+' || ch == '-' || ch == '*' {
45+
let left = Solution::helper(&input[..i]);
46+
let right = Solution::helper(&input[i+1..]);
47+
for &a in left.iter() {
48+
for &b in right.iter() {
49+
res.push(match ch {
50+
'+' => a + b,
51+
'-' => a - b,
52+
'*' => a * b,
53+
_ => unreachable!(),
54+
})
55+
}
56+
}
57+
}
58+
}
59+
res
60+
}
61+
}
62+
63+
// submission codes end
64+
65+
#[cfg(test)]
66+
mod tests {
67+
use super::*;
68+
69+
#[test]
70+
fn test_241() {
71+
assert_eq!(Solution::diff_ways_to_compute("2*3-4*5".to_owned()), vec![-34, -10, -14, -10, 10]);
72+
}
73+
}

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