longest common subsequence added.

Author: Harsh Gupta

dynamic_programming/longest common subsequence/input.txt

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+1
+AGGTAB GXTXAYB

dynamic_programming/longest common subsequence/main.cpp

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+/*
+* Note: This template uses some c++11 functions , so you have to compile it with c++11 flag.
+*       Example:-   $ g++ -std=c++11 c++Template.cpp
+*
+* Author : Harsh Gupta
+* Handle: harshsavasil
+*
+*/
+
+/*
+Problem Description: Longest Common Subsequence
+Given two sequences, find the length of longest subsequence present in both of them.
+A subsequence is a sequence that appears in the same relative order, but not necessarily contiguous.
+For example, “abc”, “abg”, “bdf”, “aeg”, ‘”acefg”, .. etc are subsequences of “abcdefg”.
+So a string of length n has 2^n-1 different possible subsequences.
+
+Tags: Dynamic Programming, Recursion
+
+Sample Input - 
+1
+AGGTAB GXTXAYB
+
+Sample Output -
+4
+TC - O(n^2)
+SC - O(n^2)
+*/
+#include <iostream>
+#include <sstream>
+#include <cstdio>
+#include <cmath>
+#include <cstring>
+#include <cctype>
+#include <string>
+#include <vector>
+#include <list>
+#include <set>
+#include <map>
+#include <queue>
+#include <stack>
+#include <algorithm>
+#include <functional>
+
+using namespace std;
+
+#define DEBUG(x) cout << '>' << #x << ':' << x << endl;
+#define REP(i, n) for (int i = 0; i < (n); i++)
+#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
+#define FORD(i, a, b) for (int i = (a); i >= (b); i--)
+inline bool EQ(double a, double b)
+{
+    return fabs(a - b) < 1e-9;
+}
+const int INF = 1 << 29;
+typedef long long ll;
+typedef pair<int, int> ii;
+typedef vector<ii> vii;
+typedef vector<int> vi;
+typedef vector<vector<int>> vvi;
+inline int two(int n) { return 1 << n; }
+inline int test(int n, int b) { return (n >> b) & 1; }
+inline void set_bit(int &n, int b) { n |= two(b); }
+inline void unset_bit(int &n, int b) { n &= ~two(b); }
+inline int last_bit(int n) { return n & (-n); }
+inline int ones(int n)
+{
+    int res = 0;
+    while (n && ++res)
+        n -= n & (-n);
+    return res;
+}
+template <class T>
+void chmax(T &a, const T &b) { a = max(a, b); }
+template <class T>
+void chmin(T &a, const T &b) { a = min(a, b); }
+
+/////////////////////////////////////////////////////////////////////
+void display(const vvi data)
+{
+    int row = data.size();
+    int column = data[0].size();
+    for (int i = 0; i < row; i++)
+    {
+        for (int j = 0; j < column; j++)
+        {
+            cout << data[i][j] << ' ';
+        }
+        cout << endl;
+    }
+    cout << endl;
+}
+
+int main()
+{
+    freopen("input.txt", "r", stdin);
+    freopen("output.txt", "w", stdout);
+    int tc;
+    cin >> tc;
+    while (tc--)
+    {
+        // cout << 'Case ' << tc << endl;
+        string a, b;
+        cin >> a >> b;
+        int a_size = a.size();
+        int b_size = b.size();
+        vvi lcs(a_size + 1, vi(b_size + 1, 0));
+        for (int i = 0; i <= a_size; i++)
+        {
+            for (int j = 0; j <= b_size; j++)
+            {
+                if (i == 0 || j == 0)
+                {
+                    lcs[i][j] = 0;
+                }
+                else
+                {
+                    if (a[i - 1] == b[j - 1])
+                    {
+                        lcs[i][j] = 1 + lcs[i - 1][j - 1];
+                    }
+                    else
+                    {
+                        lcs[i][j] = max(lcs[i - 1][j], lcs[i][j - 1]);
+                    }
+                }
+            }
+        }
+        display(lcs);
+        cout << "Length of LCS : " << lcs[a_size][b_size] << endl;
+    }
+    return 0;
+}

dynamic_programming/longest common subsequence/output.txt

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+0 0 0 0 0 0 0 0 
+0 0 0 0 0 1 1 1 
+0 1 1 1 1 1 1 1 
+0 1 1 1 1 1 1 1 
+0 1 1 2 2 2 2 2 
+0 1 1 2 2 3 3 3 
+0 1 1 2 2 3 3 4 
+
+Length of LIS : 4