969. 煎饼排序

src/main.rs

@@ -1,44 +1,28 @@
-mod tree;
-use std::rc::Rc;
-use std::cell::RefCell;
-use std::collections::HashMap;
-use tree::{TreeNode, build_tree};
-
 struct Solution;
 
 impl Solution {
-    fn dfs(root: Option<Rc<RefCell<TreeNode>>>, target: i64) -> (HashMap<i64,i32>,i32) {
-        if root.is_none() {
-            return (HashMap::new(),0);
+    pub fn pancake_sort(arr: Vec<i32>) -> Vec<i32> {
+        let mut arr = arr;
+        let mut ans = vec![];
+        for i in (1..arr.len()+1).rev() {
+            if arr[i-1] == i as i32 {
+                continue;
             }
-        let node = root.unwrap();
-        let val = node.borrow().val;
-        let val = val as i64;
-        let mut ans = if val == target { 1 } else { 0 };
-        let (left,left_ans) = Self::dfs(node.borrow().left.clone(), target);
-        let (right, right_ans) = Self::dfs(node.borrow().right.clone(), target);
-        ans += left_ans + right_ans;
-        ans += *left.get(&(target - val)).unwrap_or(&0);
-        ans += *right.get(&(target - val)).unwrap_or(&0);
-        let mut map = HashMap::new();
-        map.insert(val, 1);
-        for (k,v) in left.iter().chain(right.iter()) {
-            *map.entry(k + val).or_insert(0) += v;
+            let mut index = 0;
+            while arr[index] != i as i32 {
+                index += 1;
             }
-        (map,ans)
+            ans.push((index + 1) as i32);
+            arr[0..index + 1].reverse();
+            ans.push(i as i32);
+            arr[0..i].reverse();
+            println!("{:?}", arr);
         }
-    pub fn path_sum(root: Option<Rc<RefCell<TreeNode>>>, target_sum: i32) -> i32 {
-        let (_,ans) = Self::dfs(root, target_sum as i64);
         ans
     }
 }
 
 fn main() {
-    let vals = vec![
-        Some(10), Some(5), Some(-3), Some(3), Some(2), None, Some(11),
-        Some(3), Some(-2), None, Some(1)
-    ];
-    let root = build_tree(&vals);
-    let sl = Solution::path_sum(root, 8);
+    let sl = Solution::pancake_sort(vec![3, 2, 4, 1]);
     println!("{:?}", sl);
 }