kk

src/main/java/com/dota/arr/_2873/Solution.java

@@ -0,0 +1,16 @@
+package com.dota.arr._2873;
+
+class Solution {
+	public long maximumTripletValue(int[] nums) {
+		long res = 0;
+		long max = Math.max(nums[0], nums[1]);
+		long num = nums[0] - nums[1];
+		int n = nums.length;
+		for (int i = 2; i < n; i++) {
+			res = Math.max(res, num * nums[i]);
+			num = Math.max(num, max - nums[i]);
+			max = Math.max(max, nums[i]);
+		}
+		return res;
+	}
+}

src/main/java/com/dota/dp/_1177/Solution.java

@@ -0,0 +1,21 @@
+package com.dota.dp._1177;
+
+import java.util.ArrayList;
+import java.util.List;
+
+class Solution {
+	public List<Boolean> canMakePaliQueries(String s, int[][] queries) {
+		List<Boolean> list = new ArrayList<>();
+		int n = s.length();
+		var dp = new int[n + 1];
+		for (int i = 0; i < s.length(); i++) {
+			dp[i + 1] = dp[i] ^ (1 << s.charAt(i) - 'a') ;
+		}
+
+		for (int[] query : queries) {
+			int l = query[0], r = query[1], k = query[2];
+			list.add(Integer.bitCount(dp[l] ^ dp[r+1]) / 2 <= k);
+		}
+		return list;
+	}
+}

src/main/java/com/dota/hard/_1542/Solution.java

@@ -0,0 +1,25 @@
+package com.dota.hard._1542;
+
+import java.util.Arrays;
+
+class Solution {
+    public int longestAwesome(String s) {
+        int n = s.length();
+        int[] pos = new int[1 << 10];
+        Arrays.fill(pos, n); // n 表示没有找到异或前缀和
+        pos[0] = -1; // pre[-1] = 0
+        int ans = 0;
+        int pre = 0;
+        for (int i = 0; i < n; i++) {
+            pre ^= 1 << (s.charAt(i) - '0');
+            for (int d = 0; d < 10; d++) {
+                ans = Math.max(ans, i - pos[pre ^ (1 << d)]); // 奇数
+            }
+            ans = Math.max(ans, i - pos[pre]); // 偶数
+            if (pos[pre] == n) { // 首次遇到值为 pre 的前缀异或和，记录其下标 i
+                pos[pre] = i;
+            }
+        }
+        return ans;
+    }
+}

src/main/java/com/dota/str/_1542/Solution.java

@@ -0,0 +1,34 @@
+package com.dota.str._1542;
+
+class Solution {
+    public int longestAwesome(String s) {
+        int sum = 0;
+        for (int i = 0; i < s.length(); i++) {
+            for (int j = i; j < s.length(); j++) {
+                if (check(s,i,j+1)) {
+                    sum = Math.max(sum, j-i+1);
+                }
+            }
+
+        }
+        return sum;
+    }
+
+    boolean check(String s, int l, int r) {
+        int[] dp = new int[10];
+        for (int i =l;i<r;i++) {
+            dp[s.charAt(i)-'0']++;
+        }
+
+        boolean flag = false;
+        for (int i = 0; i < 10; i++) {
+            if (dp[i] % 2 ==1) {
+                if (flag) {
+                    return false;
+                }
+                flag = true;
+            }
+        }
+        return true;
+    }
+}