diff --git "a/leetcode3/\354\240\225\354\247\204\354\230\201/357. Count Numbers with Unique Digits" "b/leetcode3/\354\240\225\354\247\204\354\230\201/357. Count Numbers with Unique Digits"
new file mode 100644
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--- /dev/null
+++ "b/leetcode3/\354\240\225\354\247\204\354\230\201/357. Count Numbers with Unique Digits"	
@@ -0,0 +1,25 @@
+/**
+ * @param {number} n
+ * @return {number}
+ */
+var countNumbersWithUniqueDigits = function(n) {
+    let ans = 10;
+    let count = 9;
+    if (n == 0){
+        return 1;
+    } else if (n==1) {
+        return ans;
+    } else {
+        // 한자리수 0~9 -> 10개
+        // 2자리수 1~9 -> 9개 * 9개(0~9 중 첫째자리 제외)
+        // 3자리수 9 * 9 * 8
+        // 9*9*8*7
+        let next = 9;
+        for (let i = 2; i <= n; i++){ // n==3 
+           count = count * next; // count = 9*9 count = 9*9*8
+           ans = ans + count;   // 81+10
+           next--;  // 8
+        }
+    }
+    return ans;
+};
diff --git "a/leetcode3/\354\240\225\354\247\204\354\230\201/70. Climbing Stairs" "b/leetcode3/\354\240\225\354\247\204\354\230\201/70. Climbing Stairs"
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--- /dev/null
+++ "b/leetcode3/\354\240\225\354\247\204\354\230\201/70. Climbing Stairs"	
@@ -0,0 +1,15 @@
+/**
+ * @param {number} n
+ * @return {number}
+ */
+var climbStairs = function(n) {
+    // dp
+    // 시간복잡도: O(n) (for문)
+    const dp = [];
+    dp[0] = 1;
+    dp[1] = 1;
+    for (let i = 2; i <= n; i++){
+        dp[i] = dp[i-1] + dp[i-2];
+    }
+    return dp[n];
+};