diff --git a/homework/counts.java b/homework/counts.java
new file mode 100644
index 0000000..ba5ec06
--- /dev/null
+++ b/homework/counts.java
@@ -0,0 +1,30 @@
+public class counts{
+    public static void main(String[] args){
+     int [] numbers = new int[100];
+     int [] counts = new int[10];
+
+   for(int i = 0; i<numbers.length; i++){
+            numbers[i] = (int)(Math.random()*10);
+            System.out.print(numbers[i]);       
+    }
+     System.out.print("\n"); 
+       System.out.println("each numbers is occur: \n");   
+ 
+           int count = 0;
+           for(int k =0; k< counts.length;k++) {
+             for(int i = 0; i<numbers.length; i++){
+              if(k == numbers[i])
+              count++;
+            }
+             counts[k] = count;
+             count = 0;
+       }      
+
+         for(int k = 0; k< counts.length; k ++)
+      System.out.println(k + ":"+counts[k]);
+
+
+}
+}
+  
+  
\ No newline at end of file
diff --git a/homework/printMatrix.java b/homework/printMatrix.java
new file mode 100644
index 0000000..3554159
--- /dev/null
+++ b/homework/printMatrix.java
@@ -0,0 +1,23 @@
+import java.util.Scanner;
+public class printMatrix{
+    public static void main(String[] args){
+    Scanner scan = new Scanner(System.in);
+    System.out.println("请输入一个整数n");
+    int n = scan . nextInt();
+    printMatrix(n);
+ }
+     public static void printMatrix(int n ){
+       int i , j;
+     for(i =0; i< n ; i++){
+      for(j=0;j< n;j++){
+              int a = (int)((Math.random()*15)/10);
+             System.out.print(a); 
+       }
+             System.out.print("\n"); 
+     }
+}
+
+
+
+
+}
\ No newline at end of file
diff --git a/homework/reverse.java b/homework/reverse.java
new file mode 100644
index 0000000..f38d386
--- /dev/null
+++ b/homework/reverse.java
@@ -0,0 +1,24 @@
+import java.util.Scanner;
+public class reverse{
+    public static void main(String[] args){
+    Scanner scan = new Scanner(System.in);
+    System.out.println("请输入一个整数");
+    int number = scan . nextInt();
+    reverse(number);
+ }
+    public static void reverse(int number){
+      int a = 0;
+      if(number< 0 ){
+      System.out.println("非法输入!");
+    } 
+      else{
+        while(number > 0){
+          a = number % 10;
+          number = number/ 10;
+          System.out.print( a );
+    }
+       
+ }      
+             
+  }
+}
diff --git a/homework/sumMatrix.java b/homework/sumMatrix.java
new file mode 100644
index 0000000..ab18bec
--- /dev/null
+++ b/homework/sumMatrix.java
@@ -0,0 +1,31 @@
+import java.util.Scanner;
+public class sumMatrix{
+public static void main(String[] args){
+   System.out.println("import:");
+  Scanner scan = new Scanner(System.in);
+  int n = scan.nextInt();
+   double[][] matrix = new double[n][n];
+   for(int i = 0;i<matrix.length ; i++){
+    for(int j = 0; j < matrix[i].length; j++){
+   matrix[i][j] = (int)(Math.random()* 100);
+    System.out.print(matrix[i][j]+" ");
+    }
+    System.out.print("\n");
+}
+System.out.println("sum of these elements is:");
+   double sum = 0;
+   for(  int i = 0; i < matrix.length;i++){
+   for(int j = 0; j < matrix[i].length;j++){
+   if (i == j){
+    double elem = matrix[i][j];
+    sum = sum + elem;
+  
+    }
+    }
+
+  }
+System.out.println(sum );
+
+ }
+   
+ }
diff --git a/homework/temp.java b/homework/temp.java
new file mode 100644
index 0000000..36d0256
--- /dev/null
+++ b/homework/temp.java
@@ -0,0 +1,30 @@
+import java.util .Scanner; 
+public class temp{
+public static void main(String[] args){
+  System.out.println("请输入10个数字");
+  Scanner scan = new  Scanner(System.in);
+ double[ ] array = new double[10];
+  for(int i = 0 ; i<10 ; i++) {
+    double n = scan.nextDouble();
+    array[i] = n;
+     }
+      for(int i = 0; i< array.length;i++){
+     System.out.print(array[i]+ " ");
+      }
+     System.out.println( indexOfSmallestElement(array));
+}
+
+    public static int indexOfSmallestElement(double [] array){
+    double min = array[0];
+   int index = 0;
+   for(int i = 0; i< array.length;i++){
+   if(array[i]< min){
+     min = array[i];
+     index = i;
+     }
+      
+   
+   }
+    return index;
+  }
+}