69 lines
2.1 KiB
Java
69 lines
2.1 KiB
Java
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//给定一个未排序的整数数组，找到最长递增子序列的个数。
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//
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// 示例 1:
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//
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//
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//输入: [1,3,5,4,7]
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//输出: 2
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//解释: 有两个最长递增子序列，分别是 [1, 3, 4, 7] 和[1, 3, 5, 7]。
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//
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//
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// 示例 2:
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//
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//
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//输入: [2,2,2,2,2]
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//输出: 5
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//解释: 最长递增子序列的长度是1，并且存在5个子序列的长度为1，因此输出5。
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//
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//
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// 注意: 给定的数组长度不超过 2000 并且结果一定是32位有符号整数。
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// Related Topics 树状数组 线段树 数组 动态规划 👍 352 👎 0
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package leetcode.editor.cn;
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import java.util.Arrays;
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//673:最长递增子序列的个数
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class NumberOfLongestIncreasingSubsequence {
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public static void main(String[] args) {
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//测试代码
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Solution solution = new NumberOfLongestIncreasingSubsequence().new Solution();
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}
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//力扣代码
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//leetcode submit region begin(Prohibit modification and deletion)
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class Solution {
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public int findNumberOfLIS(int[] nums) {
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int N = nums.length;
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if (N <= 1) return N;
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int[] lengths = new int[N];
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int[] counts = new int[N];
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Arrays.fill(counts, 1);
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for (int j = 0; j < N; ++j) {
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for (int i = 0; i < j; ++i) {
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if (nums[i] < nums[j]) {
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if (lengths[i] >= lengths[j]) {
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lengths[j] = lengths[i] + 1;
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counts[j] = counts[i];
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} else if (lengths[i] + 1 == lengths[j]) {
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counts[j] += counts[i];
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}
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}
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}
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}
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int longest = 0, ans = 0;
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for (int length : lengths) {
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longest = Math.max(longest, length);
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}
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for (int i = 0; i < N; ++i) {
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if (lengths[i] == longest) {
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ans += counts[i];
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}
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}
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return ans;
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}
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}
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//leetcode submit region end(Prohibit modification and deletion)
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}
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