给定两个字符串s1，s2和K，找到至少长度为K的连续段形成的最长子序列的长度。
例子：
Input : s1 = aggayxysdfa
s2 = aggajxaaasdfa
k = 4
Output : 8
Explanation: aggasdfa is the longest
subsequence that can be formed by taking
consecutive segments, minimum of length 4.
Here segments are "agga" and "sdfa" which
are of length 4 which is included in making
the longest subsequence.
Input : s1 = aggasdfa
s2 = aggajasdfaxy
k = 5
Output : 5
Input: s1 = "aabcaaaa"
s2 = "baaabcd"
k = 3
Output: 4
Explanation: "aabc" is the longest subsequence that
is formed by taking segment of minimum length 3.
The segment is of length 4.
先决条件：最长的公共子序列
创建一个LCS [] []数组，其中LCS i，j表示由s1到i和s2到j的字符形成的最长公共子序列的长度，这些字符具有至少为K的连续段。创建一个cnt [] []数组，以计算公共段的长度。当s1 [i-1] == s2 [j-1]时， cnt i，j = cnt i-1，j-1 +1 。如果字符不相等，则段不相等，因此将cnt i，j标记为0。
当cnt i，j > = k时，则通过添加cnt ia，ja的值来更新lcs值，其中a是段a <= cnt i，j的长度。具有至少长度为k的连续段的最长子序列的答案将存储在lcs [n] [m]中，其中n和m为string1和string2的长度。
C++
// CPP program to find the Length of Longest
// subsequence formed by consecutive segments
// of at least length K
#include
using namespace std;
// Returns the length of the longest common subsequence
// with a minimum of length of K consecutive segments
int longestSubsequenceCommonSegment(int k, string s1,
string s2)
{
// length of strings
int n = s1.length();
int m = s2.length();
// declare the lcs and cnt array
int lcs[n + 1][m + 1];
int cnt[n + 1][m + 1];
// initialize the lcs and cnt array to 0
memset(lcs, 0, sizeof(lcs));
memset(cnt, 0, sizeof(cnt));
// iterate from i=1 to n and j=1 to j=m
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= m; j++) {
// stores the maximum of lcs[i-1][j] and lcs[i][j-1]
lcs[i][j] = max(lcs[i - 1][j], lcs[i][j - 1]);
// when both the characters are equal
// of s1 and s2
if (s1[i - 1] == s2[j - 1])
cnt[i][j] = cnt[i - 1][j - 1] + 1;
// when length of common segment is
// more than k, then update lcs answer
// by adding that segment to the answer
if (cnt[i][j] >= k) {
// formulate for all length of segments
// to get the longest subsequence with
// consecutive Common Segment of length
// of min k length
for (int a = k; a <= cnt[i][j]; a++)
// update lcs value by adding segment length
lcs[i][j] = max(lcs[i][j],
lcs[i - a][j - a] + a);
}
}
}
return lcs[n][m];
}
// driver code to check the above function
int main()
{
int k = 4;
string s1 = "aggasdfa";
string s2 = "aggajasdfa";
cout << longestSubsequenceCommonSegment(k, s1, s2);
return 0;
} Java
// Java program to find the Length of Longest
// subsequence formed by consecutive segments
// of at least length K
class GFG {
// Returns the length of the longest common subsequence
// with a minimum of length of K consecutive segments
static int longestSubsequenceCommonSegment(int k, String s1,
String s2)
{
// length of strings
int n = s1.length();
int m = s2.length();
// declare the lcs and cnt array
int lcs[][] = new int[n + 1][m + 1];
int cnt[][] = new int[n + 1][m + 1];
// iterate from i=1 to n and j=1 to j=m
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= m; j++) {
// stores the maximum of lcs[i-1][j] and lcs[i][j-1]
lcs[i][j] = Math.max(lcs[i - 1][j], lcs[i][j - 1]);
// when both the characters are equal
// of s1 and s2
if (s1.charAt(i - 1) == s2.charAt(j - 1))
cnt[i][j] = cnt[i - 1][j - 1] + 1;
// when length of common segment is
// more than k, then update lcs answer
// by adding that segment to the answer
if (cnt[i][j] >= k)
{
// formulate for all length of segments
// to get the longest subsequence with
// consecutive Common Segment of length
// of min k length
for (int a = k; a <= cnt[i][j]; a++)
// update lcs value by adding
// segment length
lcs[i][j] = Math.max(lcs[i][j],
lcs[i - a][j - a] + a);
}
}
}
return lcs[n][m];
}
// driver code to check the above function
public static void main(String[] args)
{
int k = 4;
String s1 = "aggasdfa";
String s2 = "aggajasdfa";
System.out.println(longestSubsequenceCommonSegment(k, s1, s2));
}
}
// This code is contributed by prerna saini.Python3
# Python3 program to find the Length of Longest
# subsequence formed by consecutive segments
# of at least length K
# Returns the length of the longest common subsequence
# with a minimum of length of K consecutive segments
def longestSubsequenceCommonSegment(k, s1, s2) :
# length of strings
n = len(s1)
m = len(s2)
# declare the lcs and cnt array
lcs = [[0 for x in range(m + 1)] for y in range(n + 1)]
cnt = [[0 for x in range(m + 1)] for y in range(n + 1)]
# iterate from i=1 to n and j=1 to j=m
for i in range(1, n + 1) :
for j in range(1, m + 1) :
# stores the maximum of lcs[i-1][j] and lcs[i][j-1]
lcs[i][j] = max(lcs[i - 1][j], lcs[i][j - 1])
# when both the characters are equal
# of s1 and s2
if (s1[i - 1] == s2[j - 1]):
cnt[i][j] = cnt[i - 1][j - 1] + 1;
# when length of common segment is
# more than k, then update lcs answer
# by adding that segment to the answer
if (cnt[i][j] >= k) :
# formulate for all length of segments
# to get the longest subsequence with
# consecutive Common Segment of length
# of min k length
for a in range(k, cnt[i][j] + 1) :
# update lcs value by adding
# segment length
lcs[i][j] = max(lcs[i][j],lcs[i - a][j - a] + a)
return lcs[n][m]
# Driver code
k = 4
s1 = "aggasdfa"
s2 = "aggajasdfa"
print(longestSubsequenceCommonSegment(k, s1, s2))
# This code is contributed by Nikita Tiwari.C#
// C# program to find the Length of Longest
// subsequence formed by consecutive segments
// of at least length K
using System;
class GFG {
// Returns the length of the longest common subsequence
// with a minimum of length of K consecutive segments
static int longestSubsequenceCommonSegment(int k, string s1,
string s2)
{
// length of strings
int n = s1.Length;
int m = s2.Length;
// declare the lcs and cnt array
int [,]lcs = new int[n + 1,m + 1];
int [,]cnt = new int[n + 1,m + 1];
// iterate from i=1 to n and j=1 to j=m
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= m; j++) {
// stores the maximum of lcs[i-1][j] and lcs[i][j-1]
lcs[i,j] = Math.Max(lcs[i - 1,j], lcs[i,j - 1]);
// when both the characters are equal
// of s1 and s2
if (s1[i - 1] == s2[j - 1])
cnt[i,j] = cnt[i - 1,j - 1] + 1;
// when length of common segment is
// more than k, then update lcs answer
// by adding that segment to the answer
if (cnt[i,j] >= k)
{
// formulate for all length of segments
// to get the longest subsequence with
// consecutive Common Segment of length
// of min k length
for (int a = k; a <= cnt[i,j]; a++)
// update lcs value by adding
// segment length
lcs[i,j] = Math.Max(lcs[i,j],
lcs[i - a,j - a] + a);
}
}
}
return lcs[n,m];
}
// driver code to check the above function
public static void Main()
{
int k = 4;
string s1 = "aggasdfa";
string s2 = "aggajasdfa";
Console.WriteLine(longestSubsequenceCommonSegment(k, s1, s2));
}
}
// This code is contributed by vt_m.输出：
8