add 1297

fishercoder1534 · fishercoder1534 · commit 950271d2a0a0 · 2019-12-22T07:10:21.000-08:00
diff --git a/src/main/java/com/fishercoder/solutions/_1297.java b/src/main/java/com/fishercoder/solutions/_1297.java
@@ -0,0 +1,73 @@
+package com.fishercoder.solutions;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * 1297. Maximum Number of Occurrences of a Substring
+ *
+ * Given a string s, return the maximum number of ocurrences of any substring under the following rules:
+ *
+ * The number of unique characters in the substring must be less than or equal to maxLetters.
+ * The substring size must be between minSize and maxSize inclusive.
+ *
+ * Example 1:
+ * Input: s = "aababcaab", maxLetters = 2, minSize = 3, maxSize = 4
+ * Output: 2
+ * Explanation: Substring "aab" has 2 ocurrences in the original string.
+ * It satisfies the conditions, 2 unique letters and size 3 (between minSize and maxSize).
+ *
+ * Example 2:
+ * Input: s = "aaaa", maxLetters = 1, minSize = 3, maxSize = 3
+ * Output: 2
+ * Explanation: Substring "aaa" occur 2 times in the string. It can overlap.
+ *
+ * Example 3:
+ * Input: s = "aabcabcab", maxLetters = 2, minSize = 2, maxSize = 3
+ * Output: 3
+ *
+ * Example 4:
+ * Input: s = "abcde", maxLetters = 2, minSize = 3, maxSize = 3
+ * Output: 0
+ *
+ * Constraints:
+ * 1 <= s.length <= 10^5
+ * 1 <= maxLetters <= 26
+ * 1 <= minSize <= maxSize <= min(26, s.length)
+ * s only contains lowercase English letters.
+ * */
+public class _1297 {
+    public static class Solution1 {
+        public int maxFreq(String s, int maxLetters, int minSize, int maxSize) {
+            int maxFreq = 0;
+            for (int size = minSize; size <= maxSize; size++) {
+                maxFreq = Math.max(maxFreq, getMaxFreqWithThisSize(s, maxLetters, size));
+            }
+            return maxFreq;
+        }
+
+        private int getMaxFreqWithThisSize(String str, int maxLetters, int size) {
+            Map<String, Integer> map = new HashMap<>();
+            for (int i = 0; i <= str.length() - size; i++) {
+                String substring = str.substring(i, i + size);
+                Set<Character> set = new HashSet<>();
+                for (int j = 0; j < substring.length(); j++) {
+                    set.add(substring.charAt(j));
+                    if (set.size() > maxLetters) {
+                        break;
+                    }
+                }
+                if (set.size() <= maxLetters) {
+                    map.put(substring, map.getOrDefault(substring, 0) + 1);
+                }
+            }
+            int max = 0;
+            for (String key : map.keySet()) {
+                max = Math.max(max, map.get(key));
+            }
+            return max;
+        }
+    }
+}
