1+ // Problem : A substring of a string is a subsequence in which all the characters are consecutive.Given two strings,
2+ // we need to find the longest common substring.
3+ 4+ // Approach :
5+ 6+ // We are creating a 2d dp array corresponding to the dimensions of the array. Now if the characters for a pair of
7+ // i, j are not equal, that show that they can be included in the final answer and hence they are discarded.
8+ // Else, we take a look at dp[i-1][j-1] if the continuity is maintained the we can find a continous equal substring
9+ // or not.
10+ 11+ #include < bits/stdc++.h>
12+ using namespace std ;
13+ 14+ int lcs (string &s1, string &s2)
15+ {
16+ int n = s1.size ();
17+ int m = s2.size ();
18+ vector<vector<int >> dp (n + 1 , vector<int >(m + 1 , 0 ));
19+ int ans = 0 ;
20+ for (int i = 1 ; i <= n; i++)
21+ {
22+ for (int j = 1 ; j <= m; j++)
23+ {
24+ if (s1[i - 1 ] == s2[j - 1 ])
25+ {
26+ // looking if just previous characters are also equal or not
27+ int val = 1 + dp[i - 1 ][j - 1 ];
28+ dp[i][j] = val;
29+ ans = max (ans, val);
30+ }
31+ else
32+ {
33+ // not a part of equal substring, hence 0
34+ dp[i][j] = 0 ;
35+ }
36+ }
37+ }
38+ return ans;
39+ }
40+ 41+ int main ()
42+ {
43+ string s1;
44+ string s2;
45+ cin >> s1 >> s2;
46+ cout << " The Length of Longest Common Substring is " lcs (s1, s2);
47+ }
48+ 49+ // Sample Inputs
50+ 51+ // abcjklp
52+ // acjkp
53+ 54+ // Corresponding Outputs
55+ 56+ // 3
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