modify code

Author: algorithmzuo

src/class42/Code02_ThrowChessPiecesProblem.java

@@ -4,6 +4,7 @@
 // 方法1和方法2会超时
 // 方法3勉强通过
 // 方法4打败100%
+// 方法5打败100%，方法5是在方法4的基础上做了进一步的常数优化
 public class Code02_ThrowChessPiecesProblem {
 
 public static int superEggDrop1(int kChess, int nLevel) {
@@ -91,6 +92,26 @@ public static int superEggDrop3(int kChess, int nLevel) {
 }
 
 public static int superEggDrop4(int kChess, int nLevel) {
+if (nLevel < 1 || kChess < 1) {
+return 0;
+}
+int[] dp = new int[kChess];
+int res = 0;
+while (true) {
+res++;
+int previous = 0;
+for (int i = 0; i < dp.length; i++) {
+int tmp = dp[i];
+dp[i] = dp[i] + previous + 1;
+previous = tmp;
+if (dp[i] >= nLevel) {
+return res;
+}
+}
+}
+}
+
+public static int superEggDrop5(int kChess, int nLevel) {
 if (nLevel < 1 || kChess < 1) {
 return 0;
 }
@@ -134,7 +155,8 @@ public static void main(String[] args) {
 int ans2 = superEggDrop2(K, N);
 int ans3 = superEggDrop3(K, N);
 int ans4 = superEggDrop4(K, N);
-if (ans2 != ans3 || ans2 != ans4) {
+int ans5 = superEggDrop5(K, N);
+if (ans2 != ans3 || ans4 != ans5 || ans2 != ans4) {
 System.out.println("出错了!");
 }
 }