最長遞增子序列
最長遞增子序列是一個子序列,其中某個專案項大於其前一個專案項。在此,我們將嘗試找到一組整數中的最長遞增子序列長度。
輸入輸出
Input: A set of integers. {0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15} Output: The length of longest increasing subsequence. Here it is 6. The subsequence is 0, 2, 6, 9, 13, 15.
演算法
longestSubSeq(subarray, n)
輸入 − 子陣列和子陣列的大小。
輸出 − 最長遞增子序列長度。
Begin define array length of size n initially set 0 to all entries of length for i := 1 to n-1, do for j := 0 to i-1, do if subarray[j] < subarray[i] and length[j] > length[i], then length[i] := length[j] done increase length[i] by 1 done lis := 0 for i := 0 to n-1, do lis := maximum of lis and length[i] done return lis End
範例
#include <iostream> using namespace std; int longestSubSeq(int subArr[], int n) { int length[n] = { 0 }; //set all length to 0 length[0] = 1; //subsequence ending with subArr[0] is 1 for (int i = 1; i < n; i++) { //ignore first character, second to all for (int j = 0; j < i; j++) { //subsequence ends with subArr[j] if (subArr[j] < subArr[i] && length[j] > length[i]) length[i] = length[j]; } length[i]++; //add arr[i] } int lis = 0; for (int i = 0; i<n; i++) // find longest increasing subsequence lis = max(lis, length[i]); return lis; } int main() { int arr[] = { 0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15}; int n = 16 cout << "Length of Longest Increasing Subsequence is: " << longestSubSeq(arr, n); return 0; }
輸出
Length of Longest Increasing Subsequence is: 6
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