Create 1743-restore-the-array-from-adjacent-pairs.rs

Author: memorycancel

1743-restore-the-array-from-adjacent-pairs.rs

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+pub fn restore_array(adjacent_pairs: Vec<Vec<i32>>) -> Vec<i32> {
+    use std::collections::HashMap;
+    let mut mmp = HashMap::new();
+    for p in adjacent_pairs {
+        mmp.entry(p[0]).or_insert(Vec::new()).push(p[1]);
+        mmp.entry(p[1]).or_insert(Vec::new()).push(p[0]);
+    }
+    let mut head = 0;
+    for (k, v) in &mmp {
+        if v.len() == 1 {
+            head = *k;
+            break;
+        }
+    }
+    // Firstly, find the head or tail
+    let mut ret = vec![head];
+    let mut count = 1;
+    let mut prev = head;
+    loop {
+        let current = ret.iter().last().unwrap().clone();
+        let item = &mmp[&current];
+        if item.len() == 1 {
+            ret.push(item[0]);
+        } else {
+            if item[0] == prev {
+                ret.push(item[1]);
+            } else {
+                ret.push(item[0]);
+            }
+        }
+        prev = current;
+        count += 1;
+        if count == mmp.len() { break }
+    }
+    ret
+}
+
+fn main() {
+    let adjacent_pairs = vec![vec![2,1], vec![3,4], vec![3,2]];
+    println!("{:?}", restore_array(adjacent_pairs));
+}