leet-code/src/main/java/leetcode/editor/cn/MakeTheXorOfAllSegmentsEqualToZero.java

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//给你一个整数数组 nums 和一个整数 k 。区间 [left, right]left <= right的 异或结果 是对下标位于 left 和 rig
//ht包括 left 和 right )之间所有元素进行 XOR 运算的结果nums[left] XOR nums[left+1] XOR ... XOR n
//ums[right] 。
//
// 返回数组中 要更改的最小元素数 ,以使所有长度为 k 的区间异或结果等于零。
//
//
//
// 示例 1
//
//
//输入nums = [1,2,0,3,0], k = 1
//输出3
//解释:将数组 [1,2,0,3,0] 修改为 [0,0,0,0,0]
//
//
// 示例 2
//
//
//输入nums = [3,4,5,2,1,7,3,4,7], k = 3
//输出3
//解释:将数组 [3,4,5,2,1,7,3,4,7] 修改为 [3,4,7,3,4,7,3,4,7]
//
//
// 示例 3
//
//
//输入nums = [1,2,4,1,2,5,1,2,6], k = 3
//输出3
//解释:将数组[1,2,4,1,2,5,1,2,6] 修改为 [1,2,3,1,2,3,1,2,3]
//
//
//
// 提示:
//
//
// 1 <= k <= nums.length <= 2000
// 0 <= nums[i] < 210
//
// Related Topics 动态规划
// 👍 57 👎 0
package leetcode.editor.cn;
import java.util.*;
//1787:使所有区间的异或结果为零
public class MakeTheXorOfAllSegmentsEqualToZero {
public static void main(String[] args) {
//测试代码
Solution solution = new MakeTheXorOfAllSegmentsEqualToZero().new Solution();
//3
System.out.println(solution.minChanges(new int[]{1,2,0,3,0},1));
//3
System.out.println(solution.minChanges(new int[]{3,4,5,2,1,7,3,4,7},3));
//3
System.out.println(solution.minChanges(new int[]{1, 2, 4, 1, 2, 5, 1, 2, 6}, 3));
//11
System.out.println(solution.minChanges(new int[]{26,19,19,28,13,14,6,25,28,19,0,15,25,11}, 3));
//11
System.out.println(solution.minChanges(new int[]{11,20,3,18,26,30,20,7,3,0,25,9,19,21,3,23}, 5));
}
//力扣代码
//leetcode submit region begin(Prohibit modification and deletion)
class Solution {
public int minChanges(int[] nums, int k) {
List<Map<Integer, Integer>> list = new ArrayList<>();
for (int i = 0; i < k; i++) {
list.add(new HashMap<>());
}
for (int i = 0; i < nums.length; i++) {
int index = i % k;
Map<Integer, Integer> map = list.get(index);
map.put(nums[i], map.getOrDefault(nums[i], 0) + 1);
list.set(index, map);
}
int[] flag = new int[1 << 10];
Arrays.fill(flag, Integer.MAX_VALUE / 2);
flag[0] = 0;
int length = nums.length % k == 0 ? nums.length / k : nums.length / k + 1;
for (int i = 0; i < k; i++) {
Map<Integer, Integer> map = list.get(i);
int min = Arrays.stream(flag).min().getAsInt();
int[] temp = new int[1 << 10];
Arrays.fill(temp, min);
for (int j = 0; j < (1 << 10); j++) {
for (int key : map.keySet()) {
temp[j] = Math.min(temp[j], flag[j ^ key] - map.get(key));
}
temp[j] += i < nums.length % k || nums.length % k == 0 ? length : length - 1;
}
flag = temp;
}
return flag[0];
}
}
//leetcode submit region end(Prohibit modification and deletion)
}