add: CuttingWood

Author: Jer3myYu

java/Binary Search/CuttingWood.java

@@ -0,0 +1,31 @@
+import java.util.Arrays;
+
+public class CuttingWood {
+    public int cuttingwood(int[] heights, int k) {
+        int left = 0;
+        int right = Arrays.stream(heights).max().getAsInt();
+        while (left < right) {
+            // Bias the midpoint to the right during the upper-bound binary 
+            // search.
+            int mid = (left + right) / 2 + 1;
+            if (cutsEnoughWood(mid, k, heights)) {
+                left = mid;
+            } else {
+                right = mid - 1;
+            }
+        }
+        return right;
+    }
+
+    // Determine if the current value of 'H' cuts at least 'k' meters of 
+    // wood.
+    private boolean cutsEnoughWood(int H, int k, int[] heights) {
+        int woodCollected = 0;
+        for (int height : heights) {
+            if (height > H) {
+                woodCollected += (height - H);
+            }
+        }
+        return woodCollected >= k;
+    }
+}