Create 1888-minimum-number-of-flips-to-make-the-binary-string-alternating.java

ahmedayyad89 · ahmedayyad89 · commit 973d49482d56 · 2024-04-03T12:02:24.000+02:00
diff --git a/java/1888-minimum-number-of-flips-to-make-the-binary-string-alternating.java b/java/1888-minimum-number-of-flips-to-make-the-binary-string-alternating.java
@@ -0,0 +1,39 @@
+class Solution {
+    public int minFlips(String s) {
+        int n = s.length();
+        s += s;
+
+        StringBuilder alt1 = new StringBuilder();
+        StringBuilder alt2 = new StringBuilder();
+
+        for (int i = 0; i < s.length(); i++) {
+            alt1.append(i % 2 == 0 ? '0' : '1');
+            alt2.append(i % 2 == 0 ? '1' : '0');
+        }
+
+        int res = Integer.MAX_VALUE;
+        int diff1 = 0, diff2 = 0;
+        int l = 0;
+        for (int r = 0; r < s.length(); r++) {
+            if (s.charAt(r) != alt1.charAt(r)) {
+                diff1++;
+            }
+            if (s.charAt(r) != alt2.charAt(r)) {
+                diff2++;
+            }
+            if ((r - l + 1) > n) {
+                if (s.charAt(l) != alt1.charAt(l)) {
+                    diff1--;
+                }
+                if (s.charAt(l) != alt2.charAt(l)) {
+                    diff2--;
+                }
+                l++;
+            }
+            if ((r - l + 1) == n) {
+                res = Math.min(res, Math.min(diff1, diff2));
+            }
+        }
+        return res;
+    }
+}
