diff --git a/solution/0600-0699/0670.Maximum Swap/README.md b/solution/0600-0699/0670.Maximum Swap/README.md
index bdd3bdd7d42a4..a0806f2766415 100644
--- a/solution/0600-0699/0670.Maximum Swap/README.md	
+++ b/solution/0600-0699/0670.Maximum Swap/README.md	
@@ -235,4 +235,58 @@ impl Solution {
 
 <!-- solution:end -->
 
+<!-- solution:start -->
+
+### 方法二：贪心 + 空间优化
+
+<!-- tabs:start -->
+
+#### TypeScript
+
+```ts
+function maximumSwap(num: number): number {
+    const ans = [...String(num)];
+    let [min, max, maybeMax, n] = [-1, -1, -1, ans.length];
+
+    for (let i = n - 1; i >= 0; i--) {
+        if (ans[i] > (ans[maybeMax] ?? -1)) maybeMax = i;
+        if (i < maybeMax && ans[i] < ans[maybeMax]) {
+            [min, max] = [i, maybeMax];
+        }
+    }
+
+    if (~min && ~max && min < max) {
+        [ans[min], ans[max]] = [ans[max], ans[min]];
+    }
+
+    return +ans.join('');
+}
+```
+
+#### JavaScript
+
+```js
+function maximumSwap(num) {
+    const ans = [...String(num)];
+    let [min, max, maybeMax, n] = [-1, -1, -1, ans.length];
+
+    for (let i = n - 1; i >= 0; i--) {
+        if (ans[i] > (ans[maybeMax] ?? -1)) maybeMax = i;
+        if (i < maybeMax && ans[i] < ans[maybeMax]) {
+            [min, max] = [i, maybeMax];
+        }
+    }
+
+    if (~min && ~max && min < max) {
+        [ans[min], ans[max]] = [ans[max], ans[min]];
+    }
+
+    return +ans.join('');
+}
+```
+
+<!-- tabs:end -->
+
+<!-- solution:end -->
+
 <!-- problem:end -->
diff --git a/solution/0600-0699/0670.Maximum Swap/README_EN.md b/solution/0600-0699/0670.Maximum Swap/README_EN.md
index 8f722d5214098..cd4b834a6fdcb 100644
--- a/solution/0600-0699/0670.Maximum Swap/README_EN.md	
+++ b/solution/0600-0699/0670.Maximum Swap/README_EN.md	
@@ -239,4 +239,58 @@ impl Solution {
 
 <!-- solution:end -->
 
+<!-- solution:start -->
+
+### Solution 2: Space Optimized Greedy
+
+<!-- tabs:start -->
+
+#### TypeScript
+
+```ts
+function maximumSwap(num: number): number {
+    const ans = [...String(num)];
+    let [min, max, maybeMax, n] = [-1, -1, -1, ans.length];
+
+    for (let i = n - 1; i >= 0; i--) {
+        if (ans[i] > (ans[maybeMax] ?? -1)) maybeMax = i;
+        if (i < maybeMax && ans[i] < ans[maybeMax]) {
+            [min, max] = [i, maybeMax];
+        }
+    }
+
+    if (~min && ~max && min < max) {
+        [ans[min], ans[max]] = [ans[max], ans[min]];
+    }
+
+    return +ans.join('');
+}
+```
+
+#### JavaScript
+
+```js
+function maximumSwap(num) {
+    const ans = [...String(num)];
+    let [min, max, maybeMax, n] = [-1, -1, -1, ans.length];
+
+    for (let i = n - 1; i >= 0; i--) {
+        if (ans[i] > (ans[maybeMax] ?? -1)) maybeMax = i;
+        if (i < maybeMax && ans[i] < ans[maybeMax]) {
+            [min, max] = [i, maybeMax];
+        }
+    }
+
+    if (~min && ~max && min < max) {
+        [ans[min], ans[max]] = [ans[max], ans[min]];
+    }
+
+    return +ans.join('');
+}
+```
+
+<!-- tabs:end -->
+
+<!-- solution:end -->
+
 <!-- problem:end -->
diff --git a/solution/0600-0699/0670.Maximum Swap/Solution2.js b/solution/0600-0699/0670.Maximum Swap/Solution2.js
new file mode 100644
index 0000000000000..5f96574097e85
--- /dev/null
+++ b/solution/0600-0699/0670.Maximum Swap/Solution2.js	
@@ -0,0 +1,17 @@
+function maximumSwap(num) {
+    const ans = [...String(num)];
+    let [min, max, maybeMax, n] = [-1, -1, -1, ans.length];
+
+    for (let i = n - 1; i >= 0; i--) {
+        if (ans[i] > (ans[maybeMax] ?? -1)) maybeMax = i;
+        if (i < maybeMax && ans[i] < ans[maybeMax]) {
+            [min, max] = [i, maybeMax];
+        }
+    }
+
+    if (~min && ~max && min < max) {
+        [ans[min], ans[max]] = [ans[max], ans[min]];
+    }
+
+    return +ans.join('');
+}
diff --git a/solution/0600-0699/0670.Maximum Swap/Solution2.ts b/solution/0600-0699/0670.Maximum Swap/Solution2.ts
new file mode 100644
index 0000000000000..9784bc33c8e87
--- /dev/null
+++ b/solution/0600-0699/0670.Maximum Swap/Solution2.ts	
@@ -0,0 +1,17 @@
+function maximumSwap(num: number): number {
+    const ans = [...String(num)];
+    let [min, max, maybeMax, n] = [-1, -1, -1, ans.length];
+
+    for (let i = n - 1; i >= 0; i--) {
+        if (ans[i] > (ans[maybeMax] ?? -1)) maybeMax = i;
+        if (i < maybeMax && ans[i] < ans[maybeMax]) {
+            [min, max] = [i, maybeMax];
+        }
+    }
+
+    if (~min && ~max && min < max) {
+        [ans[min], ans[max]] = [ans[max], ans[min]];
+    }
+
+    return +ans.join('');
+}