Completed both the problems

diagonal traverse.java

@@ -0,0 +1,37 @@
+class Solution {
+    public int[] findDiagonalOrder(int[][] mat) {
+        int m = mat.length;
+        int n = mat[0].length;
+        int r =0; 
+        int c = 0;
+        int[] res = new int[m*n];
+        boolean dir = true; // moves up
+        for(int i =0; i< m*n; i++) {
+            res[i]=mat[r][c];
+            if(dir == true) {
+                if(c== n-1) {
+                r++;
+                dir= false;
+                } else if(r==0){
+                    c++;
+                    dir = false;
+                } else {
+                    r--;
+                    c++;
+                }
+            } else {
+                if(r==m-1) {
+                c++;
+                dir = true;
+                } else if(c==0){
+                    r++;
+                    dir = true;
+                } else {
+                 r++;
+                 c--;
+                }
+            }
+        }
+        return res;
+    }
+}

product of array except self.java

@@ -0,0 +1,18 @@
+class Solution {
+    public int[] productExceptSelf(int[] nums) {
+        int n = nums.length;
+        int[] lp = new int[n];
+        int rp = 1;
+        lp[0] = 1;
+        for(int i=1; i< n; i++) {
+            lp[i] = rp * nums[i-1];
+            rp = lp[i];
+        }
+        rp=1;
+        for(int j=nums.length-2; j >= 0; j--) {
+            rp = rp * nums[j+1];
+            lp[j] = lp[j] * rp;
+        }
+        return lp;
+    }
+}