diff --git a/src/main/java/com/code/leet/week/Solution248.java b/src/main/java/com/code/leet/week/Solution248.java
new file mode 100644
index 0000000..4fd3a94
--- /dev/null
+++ b/src/main/java/com/code/leet/week/Solution248.java
@@ -0,0 +1,57 @@
+package com.code.leet.week;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+public class Solution248 {
+
+    public static void main(String[] args) {
+        Solution248 solution = new Solution248();
+//        System.out.println(solution.eliminateMaximum(new int[]{1, 3, 4}, new int[]{1, 1, 1}));
+//        System.out.println(solution.eliminateMaximum(new int[]{1, 1, 2, 3}, new int[]{1, 1, 1, 1}));
+//        System.out.println(solution.eliminateMaximum(new int[]{5}, new int[]{3}));
+//        System.out.println(solution.eliminateMaximum(new int[]{4, 2, 8}, new int[]{2, 1, 4}));
+        System.out.println(solution.countGoodNumbers(50));
+    }
+
+    public int[] buildArray(int[] nums) {
+        int size = nums.length;
+        int[] arr = new int[size];
+        for (int i = 0; i < size; i++) {
+            arr[i] = nums[nums[i]];
+        }
+        return arr;
+    }
+
+    public int eliminateMaximum(int[] dist, int[] speed) {
+        int size = dist.length;
+        int[] times = new int[size];
+        for (int i = 0; i < size; i++) {
+            int time = dist[i] / speed[i];
+            times[i] = dist[i] % speed[i] == 0 ? time - 1 : time;
+        }
+        Arrays.sort(times);
+        Map<Integer, Integer> map = new HashMap<>();
+        for (int i = 0; i < size; i++) {
+            map.put(times[i], map.getOrDefault(times[i], 0) + 1);
+        }
+        int index = 1;
+        for (int i = 0; i < size; i++) {
+            if (map.containsKey(i)) {
+                if (map.get(i) > index) {
+                    return i + 1;
+                }
+                index -= map.get(i);
+            }
+            index++;
+        }
+        return size;
+    }
+
+    public int countGoodNumbers(long n) {
+        int odd = (int)(n/2);
+        int num = (int)(n-odd);
+        return (int)(Math.pow(5,num)*Math.pow(4,odd))%10000007;
+    }
+}