[minFallingPathSum + deleteAndEarn]

Sample.java

@@ -5,3 +5,82 @@
 
 
 // Your code here along with comments explaining your approach
+
+// Time Complexity : O(N^2)
+// Space Complexity : O(N)
+// Did this code successfully run on Leetcode : Yes it did
+// Challenge was to determine how to use 1D array
+
+class Sample {
+
+    public int minFallingPathSum(int[][] matrix) {
+        int n = matrix.length;
+
+        int[] prev = new int[n];
+
+        for (int j = 0; j < n; j++) {
+            prev[j] = matrix[0][j];
+        }
+
+        for (int i = 1; i < n; i++) {
+            int[] curr = new int[n];
+
+            for (int j = 0; j < n; j++) {
+                int minAbove = prev[j];
+
+                if (j > 0) {
+                    minAbove = Math.min(minAbove, prev[j - 1]);
+                }
+                if (j < n - 1) {
+                    minAbove = Math.min(minAbove, prev[j + 1]);
+                }
+
+                curr[j] = matrix[i][j] + minAbove;
+            }
+
+            prev = curr;
+        }
+
+        int ans = prev[0];
+        for (int j = 1; j < n; j++) {
+            ans = Math.min(ans, prev[j]);
+        }
+
+        return ans;
+    }
+
+    // Time Complexity : O(Max_value + N)
+    // Space Complexity : O(Max_value)
+    // Did this code successfully run on Leetcode : Yes it did
+    public int deleteAndEarn(int[] nums) {
+        if (nums.length == 0) return 0;
+
+        int max = 0;
+        for (int num : nums) {
+            max = Math.max(max, num);
+        }
+
+        // create array for points
+        int[] points = new int[max + 1];
+        for (int num : nums) {
+            points[num] += num;
+        }
+
+        int take = 0;
+        int skip = 0;
+
+        max = 0;
+
+        for (int j = 0; j < points.length; j++) {
+            if (j - 2 == 0) {
+                points[j] = points[j - 2] + points[j];
+            } else if (j - 2 > 0) {
+                points[j] = points[j - 2] > points[j - 3] ? points[j - 2] + points[j] : points[j - 3] + points[j];
+            }
+            max = Math.max(points[j], max);
+        }
+        return max;
+
+    }
+
+}