edit distance added.

Author: Harsh Gupta

dynamic_programming/edit distance/input.txt

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+3
+geek gesek
+cat cut
+sunday saturday

dynamic_programming/edit distance/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: Minimum Edit Distance
+Given two strings str1 and str2 and below operations that can performed on str1.
+Find minimum number of edits (operations) required to convert ‘str1’ into
+‘str2’. Operations - Insert Remove Replace All of the above operations are of
+equal cost.
+
+
+Tags: Strings, Dynamic Programming, Distance Measure
+
+Sample Input -
+str1 = "geek", str2 = "gesek"
+
+Sample Output -
+1
+
+Explanation - We can convert str1 into str2 by inserting a 's'.
+*/
+#include <algorithm>
+#include <cctype>
+#include <cmath>
+#include <cstdio>
+#include <cstring>
+#include <functional>
+#include <iostream>
+#include <list>
+#include <map>
+#include <queue>
+#include <set>
+#include <sstream>
+#include <stack>
+#include <string>
+#include <vector>
+
+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);
+}
+
+/////////////////////////////////////////////////////////////////////
+int main() {
+    freopen("input.txt", "r", stdin);
+    freopen("output.txt", "w", stdout);
+    int tc;
+    cin >> tc;
+    while (tc--) {
+        string a, b;
+        cin >> a >> b;
+        int a_size = a.size();
+        int b_size = b.size();
+        vvi distance(a_size + 1, vi(b_size + 1, -1));
+        distance[0][0] = 0;
+        for (int i = 0; i <= a_size; i++) {
+            for (int j = 0; j <= b_size; j++) {
+                if (i == 0 && j == 0) {
+                    distance[i][j] = 0;
+                } else if (i == 0) {
+                    distance[i][j] = j;
+                } else if (j == 0) {
+                    distance[i][j] = i;
+                } else {
+                    if (a[i - 1] == b[j - 1]) {
+                        distance[i][j] = distance[i - 1][j - 1];
+                    } else {
+                        distance[i][j] = min(distance[i - 1][j - 1], min(distance[i - 1][j], distance[i][j - 1])) + 1;
+                    }
+                }
+            }
+        }
+        cout << "Edit Distance between " << a << " and " << b << " is " << distance[a_size][b_size] << endl;
+    }
+    return 0;
+}

dynamic_programming/edit distance/output.txt

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+Edit Distance between geek and gesek is 1
+Edit Distance between cat and cut is 1
+Edit Distance between sunday and saturday is 3