refactor 70

fishercoder1534 · fishercoder1534 · commit 92f91c1a89ea · 2020-01-29T17:23:16.000-08:00
diff --git a/src/main/java/com/fishercoder/solutions/_70.java b/src/main/java/com/fishercoder/solutions/_70.java
@@ -32,22 +32,17 @@
 
 public class _70 {
   public static class Solution1 {
-    //classical dp problem
     public int climbStairs(int n) {
-      if (n < 1) {
-        return 0;
-      } else if (n < 4) {
+      if (n == 1) {
         return n;
-      } else {
-        int[] dp = new int[n + 1];
-        //the number of ways to reach step n could be calculated from n-1 and n-2
-        dp[1] = 1;
-        dp[2] = 2;
-        for (int i = 3; i <= n; i++) {
-          dp[i] = dp[i - 1] + dp[i - 2];
-        }
-        return dp[n];
       }
+      int[] dp = new int[n + 1];
+      dp[1] = 1;
+      dp[2] = 2;
+      for (int i = 3; i <= n; i++) {
+        dp[i] = dp[i - 1] + dp[i - 2];
+      }
+      return dp[n];
     }
   }
 }
