diff --git a/DiagonalTraverse.java b/DiagonalTraverse.java
new file mode 100644
index 00000000..37ef19db
--- /dev/null
+++ b/DiagonalTraverse.java
@@ -0,0 +1,33 @@
+public class DiagonalTraverse {
+    public int[] findDiagOrder(int[][] mat) {
+        int row = mat.length;
+        int col = mat[0].length;
+        int[] ans = new int[row*col];
+        int r = 0;
+        int c = 0;
+        boolean flag = true;
+        for (int i=0; i<row*col; i++){
+            ans[i] = mat[r][c];
+            if (flag) {
+                if (c==col-1) {
+                    r++; flag=false; 
+                } else if (r==0) {
+                    flag = false;
+                    c++;
+                } else {
+                    r--; c++;
+                }
+            } else {
+                if (r==row-1) {
+                    c++; flag=true;
+                } else if (c==0) {
+                    r++; flag=true;
+                } else {
+                    c--; r++;
+                }
+            }
+        }   
+        return ans;
+    }
+    
+}
diff --git a/ProductArraySelf.java b/ProductArraySelf.java
new file mode 100644
index 00000000..55b60af9
--- /dev/null
+++ b/ProductArraySelf.java
@@ -0,0 +1,17 @@
+
+class ProductArraySelf {
+    public int[] productArrayself(int[] nums) {
+        int[] ans = new int[nums.length];
+        int rProduct = 1;
+        ans[0] = 1;
+        for (int i=1; i<nums.length; i++){
+            ans[i] = ans[i-1] * nums[i-1];
+        }
+        for (int j=nums.length-2; j>=0; j--){
+            rProduct = rProduct * nums[j+1];
+            ans[j] = rProduct * ans[j];
+        }
+        return ans;
+    }
+    
+}
\ No newline at end of file