Merge pull request #128 from chipbk10/SlidingWindow

Sliding window

Author: chipbk10

src/slidingwindow/Problem1004_MaxConsecutiveOnesIII.java

@@ -0,0 +1,24 @@
+package slidingwindow;
+
+public class Problem1004_MaxConsecutiveOnesIII {
+
+    public int longestOnes(int[] A, int K) {
+        int res = 0, count = 0;
+        // 111001101111
+        for (int i = 0, j = 0; i < A.length; i++) {
+            if (A[i] == 0) {
+                K--;
+                while (K < 0) {
+                    if (A[j++] == 0) {
+                        K++;
+                    }
+                    count--;
+                }
+            }
+            count++;
+            res = Math.max(res, count);
+        }
+
+        return res;
+    }
+}

src/slidingwindow/Problem1248_CountNumberOfNiceSubarrays.java

@@ -54,4 +54,20 @@ public int numberOfSubarrays_DP(int[] A, int k) {
         }
         return res;
     }
+
+    public int numberOfSubarrays_shortVersion(int[] A, int k) {
+
+        // (l+1)*(r+1)
+        int res = 0, l = 0, count = 0;
+        for (int i = 0, j = 0; i < A.length; i++) {
+            count += A[i]%2;
+            if (count == k) l = 0;
+            while (count == k) {
+                count -= A[j++]%2;
+                l++;
+            }
+            res += l;
+        }
+        return res;
+    }
 }

src/slidingwindow/Problem1358_NumberOfSubstringsContainingAllThreeCharacters.java

@@ -0,0 +1,33 @@
+package slidingwindow;
+
+public class Problem1358_NumberOfSubstringsContainingAllThreeCharacters {
+
+    public int numberOfSubstrings(String s) {
+        // abcabc
+        // abc: 0-x = (0+1) = 1
+        // abca: 1-x = (1+1) = 2
+        // abcab: 2-x = (2+1) = 3
+        // abcabc: 3-x = (3+1) = 4
+        int na = 0, nb = 0, nc = 0, l = 0, res = 0;
+        for (int i = 0, j = 0; i < s.length(); i++) {
+            char c = s.charAt(i);
+            if (c == 'a') na++;
+            else if (c == 'b') nb++;
+            else nc++;
+
+            // if (na > 0 && nb > 0 && nc > 0) l = 0;
+
+            while (na > 0 && nb > 0 && nc > 0) {
+                c = s.charAt(j++);
+                if (c == 'a') na--;
+                else if (c == 'b') nb--;
+                else nc--;
+                l++;
+            }
+
+            res += l;
+        }
+
+        return res;
+    }
+}

src/slidingwindow/Problem424_LongestRepeatingCharacterReplacement.java

@@ -0,0 +1,17 @@
+package slidingwindow;
+
+public class Problem424_LongestRepeatingCharacterReplacement {
+
+    public int characterReplacement(String s, int k) {
+        int n = s.length(), count[] = new int[26], max = 0, j = 0;
+        for (int i = 0; i < n; i++) {
+            char c = s.charAt(i);
+            max = Math.max(max, ++count[c-'A']);
+            while (i-j+1 - max > k) {
+                c = s.charAt(j++);
+                count[c-'A']--;
+            }
+        }
+        return n-j;
+    }
+}