diff --git a/problems/0279.完全平方数.md b/problems/0279.完全平方数.md
index a00ed47e..b1af7e95 100644
--- a/problems/0279.完全平方数.md
+++ b/problems/0279.完全平方数.md
@@ -334,8 +334,8 @@ var numSquares1 = function(n) {
     let dp = new Array(n + 1).fill(Infinity)
     dp[0] = 0
 
-    for(let i = 0; i <= n; i++) {
-        let val = i * i
+    for(let i = 1; i**2 <= n; i++) {
+        let val = i**2
         for(let j = val; j <= n; j++) {
             dp[j] = Math.min(dp[j], dp[j - val] + 1)
         }