feat: update solutions to lc problems: No.1346,1486 (#2752)

Author: yanglbme

solution/1300-1399/1346.Check If N and Its Double Exist/README.md

@@ -1,12 +1,13 @@
-class Solution {
-public:
-    bool checkIfExist(vector<int>& arr) {
-        unordered_map<int, int> m;
-        int n = arr.size();
-        for (int i = 0; i < n; ++i) m[arr[i]] = i;
-        for (int i = 0; i < n; ++i)
-            if (m.count(arr[i] * 2) && m[arr[i] * 2] != i)
-                return true;
-        return false;
-    }
+class Solution {
+public:
+    bool checkIfExist(vector<int>& arr) {
+        unordered_set<int> s;
+        for (int x : arr) {
+            if (s.contains(x * 2) || (x % 2 == 0 && s.contains(x / 2))) {
+                return true;
+            }
+            s.insert(x);
+        }
+        return false;
+    }
 };

solution/1300-1399/1346.Check If N and Its Double Exist/README_EN.md

@@ -1,12 +1,10 @@
-func checkIfExist(arr []int) bool {
-	m := make(map[int]int)
-	for i, v := range arr {
-		m[v] = i
-	}
-	for i, v := range arr {
-		if j, ok := m[v*2]; ok && j != i {
-			return true
-		}
-	}
-	return false
+func checkIfExist(arr []int) bool {
+	s := map[int]bool{}
+	for _, x := range arr {
+		if s[x*2] || (x%2 == 0 && s[x/2]) {
+			return true
+		}
+		s[x] = true
+	}
+	return false
 }

solution/1300-1399/1346.Check If N and Its Double Exist/Solution.cpp

@@ -1,15 +1,12 @@
-class Solution {
-    public boolean checkIfExist(int[] arr) {
-        Map<Integer, Integer> m = new HashMap<>();
-        int n = arr.length;
-        for (int i = 0; i < n; ++i) {
-            m.put(arr[i], i);
-        }
-        for (int i = 0; i < n; ++i) {
-            if (m.containsKey(arr[i] << 1) && m.get(arr[i] << 1) != i) {
-                return true;
-            }
-        }
-        return false;
-    }
+class Solution {
+    public boolean checkIfExist(int[] arr) {
+        Set<Integer> s = new HashSet<>();
+        for (int x : arr) {
+            if (s.contains(x * 2) || ((x % 2 == 0 && s.contains(x / 2)))) {
+                return true;
+            }
+            s.add(x);
+        }
+        return false;
+    }
 }

solution/1300-1399/1346.Check If N and Its Double Exist/Solution.go

@@ -1,4 +1,8 @@
-class Solution:
-    def checkIfExist(self, arr: List[int]) -> bool:
-        m = {v: i for i, v in enumerate(arr)}
-        return any(v << 1 in m and m[v << 1] != i for i, v in enumerate(arr))
+class Solution:
+    def checkIfExist(self, arr: List[int]) -> bool:
+        s = set()
+        for x in arr:
+            if x * 2 in s or (x % 2 == 0 and x // 2 in s):
+                return True
+            s.add(x)
+        return False

solution/1300-1399/1346.Check If N and Its Double Exist/Solution.java

@@ -1,10 +1,10 @@
 function checkIfExist(arr: number[]): boolean {
-    const s = new Set();
-    for (const v of arr) {
-        if (s.has(v << 1) || s.has(v / 2)) {
+    const s: Set<number> = new Set();
+    for (const x of arr) {
+        if (s.has(x * 2) || (x % 2 === 0 && s.has((x / 2) | 0))) {
             return true;
         }
-        s.add(v);
+        s.add(x);
     }
     return false;
 }