Update 数组相关.md

blogs/Algorithm/剑指 Offer/数组相关.md

@@ -159,3 +159,55 @@ class Solution {
 }
 ```
 
+[45. 把数组排成最小的数](https://leetcode-cn.com/problems/ba-shu-zu-pai-cheng-zui-xiao-de-shu-lcof/)
+
+```java
+class Solution {
+    public String minNumber(int[] nums) {
+        String[] strings = getStringArray(nums);
+        Arrays.sort(strings, new Cop());
+
+        StringBuilder result = new StringBuilder();
+        for (String s : strings) {
+            result.append(s);
+        }
+        return result.toString();
+    }
+
+    private String[] getStringArray(int[] nums) {
+        String[] strings = new String[nums.length];
+        for (int i = 0; i < nums.length; i++) {
+            strings[i] = String.valueOf(nums[i]);
+        }
+        return strings;
+    }
+
+    class Cop implements Comparator<String> {
+        @Override
+        public int compare(String o1, String o2) {
+            String s1 = o1 + o2;
+            String s2 = o2 + o1;
+            return s1.compareTo(s2);
+        }
+    }
+}
+```
+
+```java
+class Solution {
+    public String minNumber(int[] nums) {
+        String[] strings = new String[nums.length];
+        for (int i = 0; i < nums.length; i++) {
+            strings[i] = String.valueOf(nums[i]);
+        }
+        Arrays.sort(strings, (o1, o2) -> (o1 + o2).compareTo(o2 + o1));
+
+        StringBuilder result = new StringBuilder();
+        for (String s : strings) {
+            result.append(s);
+        }
+        return result.toString();
+    }
+}
+```
+