add

interview_prep/algorithm/java/src/main/java/hoa/can/code/ez/AddBinary.java

@@ -0,0 +1,31 @@
+package hoa.can.code.ez;
+
+/**
+ * https://leetcode.com/problems/add-binary/
+ */
+public class AddBinary {
+    public String addBinary(String a, String b) {
+        StringBuilder result = new StringBuilder();
+        int carry = 0;
+        int i = a.length() - 1;
+        int j = b.length() - 1;
+
+        while (i >= 0 || j >= 0 || carry > 0) {
+            int sum = carry;
+            if (i >= 0) {
+                sum += a.charAt(i) - '0';
+                i--;
+            }
+            if (j >= 0) {
+                sum += b.charAt(j) - '0';
+                j--;
+            }
+
+            carry = sum / 2;
+            result.insert(0, sum % 2);
+        }
+
+        return result.toString();
+    }
+
+}

interview_prep/algorithm/java/src/main/java/hoa/can/code/gg/JumpingDP.java

@@ -1,29 +1,31 @@
 package hoa.can.code.gg;
 
+import static java.lang.Integer.MAX_VALUE;
+import static java.lang.Math.min;
+
 public class JumpingDP implements Jumping {
     public boolean canJump(int[] nums) {
-        return minJumps(nums) != Integer.MAX_VALUE;
+        return minJumps(nums) != MAX_VALUE;
     }
 
     public int minJumps(int[] arr) {
         int n = arr.length;
-        int[] minCostToIdx = new int[n];
+        int[] cost = new int[n];
         int i, j;
 
         if (n == 0 || arr[0] == 0)
-            return Integer.MAX_VALUE;
-
-        minCostToIdx[0] = 0;
+            return MAX_VALUE;
 
+        cost[0] = 0;
         for (i = 1; i < n; i++) {
-            minCostToIdx[i] = Integer.MAX_VALUE;
+            cost[i] = MAX_VALUE;
             for (j = 0; j < i; j++) {
-                if (i <= j + arr[j] && minCostToIdx[j] != Integer.MAX_VALUE) {
-                    minCostToIdx[i] = Math.min(minCostToIdx[i], minCostToIdx[j] + 1);
+                if (i <= j + arr[j] && cost[j] != MAX_VALUE) {
+                    cost[i] = min(cost[i], cost[j] + 1);
                     break;
                 }
             }
         }
-        return minCostToIdx[n - 1];
+        return cost[n - 1];
     }
 }

interview_prep/algorithm/java/src/test/java/hoa/can/code/AddBinaryTest.java

@@ -0,0 +1,29 @@
+package hoa.can.code;
+
+import hoa.can.code.ez.AddBinary;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class AddBinaryTest {
+    AddBinary sol = new AddBinary();
+
+    @Test
+    @DisplayName("11 + 1 = 100")
+    public void test1() {
+        assertEquals("100", sol.addBinary("11","1"));
+    }
+
+    @Test
+    @DisplayName("1 + 11 = 100")
+    public void test2() {
+        assertEquals("100", sol.addBinary("1","11"));
+    }
+
+    @Test
+    @DisplayName("11 + 1 = 100")
+    public void test3() {
+        assertEquals("10101", sol.addBinary("1010","1011"));
+    }
+}

interview_prep/algorithm/java/src/test/java/hoa/can/code/ConstraintSatisfactionProblemTest.java

@@ -45,7 +45,7 @@ public void testMapcoloring() {
         Map<String, String> solution = csp.backtrackingSearch();
 
         assertEquals(territories.size(), solution.size(), "solution found!");
-        System.out.println(solution);//preview
+        //System.out.println(solution);//preview
     }
 
     @Test