Rust: 1D_dynamic_array, 3 solutions

rust/03_sliding_window/121_best_time_to_buy.rs

@@ -1,4 +1,5 @@
-use super::std::cmp;
+use std::cmp;
+
 impl Solution {
  pub fn max_profit(prices: Vec<i32>) -> i32 {
  let mut l = 0;
@@ -7,11 +8,11 @@ impl Solution {
  while r < prices.len() {
  if prices[l] < prices[r] {
  let profit = prices[r] - prices[l];
- max_profit = cmp::max(profit, max_profit)
+ max_profit = cmp::max(profit, max_profit);
  } else {
- l = r
+ l = r;
  }
- r += 1
+ r += 1;
  }
  max_profit
  }

rust/13_1D_dynamic_programming/198_house_robber.rs

@@ -0,0 +1,18 @@
+// time complexity: O(n)
+// space complexity: O(1)
+
+impl Solution {
+ pub fn rob(mut nums: Vec<i32>) -> i32 {
+ if nums.len() == 1{
+ return nums[0];
+ }
+
+ nums[1] = nums[0].max(nums[1]);
+
+ for i in 2..nums.len(){
+ nums[i] = nums[i-1].max(nums[i - 2] + nums[i]);
+ }
+
+ *nums.last().unwrap()
+ }
+}

rust/13_1D_dynamic_programming/70_climbing_stairs.rs

@@ -0,0 +1,18 @@
+
+impl Solution {
+ pub fn climb_stairs(n: i32) -> i32 {
+ if n == 1{
+ return 1;
+ }
+
+ let (mut one, mut two) = (1, 2);
+
+ for i in 2..n{
+ let tmp = two;
+ two = two + one;
+ one = tmp;
+ }
+
+ two
+ }
+}

rust/13_1D_dynamic_programming/746_min_cost_climbing_stairs.rs

@@ -0,0 +1,14 @@
+// time compexity : O(n)
+// space compexity : O(1)
+
+impl Solution {
+ pub fn min_cost_climbing_stairs(mut cost: Vec<i32>) -> i32 {
+ for i in 2..cost.len(){
+ cost[i] += cost[i- 1].min(cost[i-2]);
+ }
+
+ let len = cost.len();
+
+ cost[len - 1].min(cost[len - 2])
+ }
+}