add 3234

Author: fishercoder1534

Diff for: paginated_contents/algorithms/4th_thousand/README.md

@@ -1,5 +1,6 @@
 | #    | Title                                                                                                                                                               | Solutions                                                                                                                         | Video                                                                         | Difficulty | Tag                                                                  
 |------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------|------------|----------------------------------------------------------------------
+| 3234 | [Count the Number of Substrings With Dominant Ones](https://leetcode.com/problems/count-the-number-of-substrings-with-dominant-ones/)                                                                 | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3234.java) |                                                                               | Medium     | Sliding Window
 | 3233 | [Find the Count of Numbers Which Are Not Special](https://leetcode.com/problems/find-the-count-of-numbers-which-are-not-special/)                                                                 | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3233.java) |                                                                               | Medium     | Math
 | 3232 | [Find if Digit Game Can Be Won](https://leetcode.com/problems/find-if-digit-game-can-be-won/)                                                                 | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3232.java) |                                                                               | Easy       |
 | 3226 | [Number of Bit Changes to Make Two Integers Equal](https://leetcode.com/problems/number-of-bit-changes-to-make-two-integers-equal/)                                                                 | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3226.java) |                                                                               | Easy       |

Diff for: src/main/java/com/fishercoder/solutions/fourththousand/_3234.java

@@ -0,0 +1,41 @@
+package com.fishercoder.solutions.fourththousand;
+
+public class _3234 {
+    public static class Solution1 {
+        /**
+         * Sliding window.
+         * credit: https://leetcode.com/problems/count-the-number-of-substrings-with-dominant-ones/solutions/5547005/sliding-window-java-o-sqrt-of-n-n/
+         * The idea is:
+         * 1. we fix the number of zeroes in each iteration, then the number of ones is zeroes * zeroes;
+         * 2. now we operate the sliding window.
+         */
+        public int numberOfSubstrings(String s) {
+            int ans = 0;
+            for (int zeroes = 0; zeroes * zeroes < s.length(); zeroes++) {
+                int[] count = new int[2];
+                int lastPos = -1;
+                //end keeps moving to the right in each iteration
+                for (int start = 0, end = 0; end < s.length(); end++) {
+                    count[s.charAt(end) - '0']++;
+                    while (start < end) {
+                        if (s.charAt(start) == '0' && count[0] > zeroes) {
+                            //this means we have more zeroes than we want, so we'll move start to the right by one
+                            count[0]--;
+                            lastPos = start;
+                        } else if (s.charAt(start) == '1' && (count[1] - 1) >= (zeroes * zeroes)) {
+                            //this means the current start position is '1' and after excluding it, the window is still a valid dominant one
+                            count[1]--;
+                        } else {
+                            break;
+                        }
+                        start++;
+                    }
+                    if (count[0] == zeroes && count[1] >= zeroes * zeroes) {
+                        ans += (start - lastPos);
+                    }
+                }
+            }
+            return ans;
+        }
+    }
+}

Diff for: src/test/java/com/fishercoder/fourththousand/_3234Test.java

@@ -0,0 +1,22 @@
+package com.fishercoder.fourththousand;
+
+import com.fishercoder.solutions.fourththousand._3234;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class _3234Test {
+    private static _3234.Solution1 solution1;
+
+    @BeforeEach
+    public void setup() {
+        solution1 = new _3234.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        assertEquals(5, solution1.numberOfSubstrings("00011"));
+    }
+
+}