Add Edit Distance in C++

Dynamic Programming/EditDistance/C++/EditDistance.cpp

@@ -0,0 +1,54 @@
+/*
+  A Dynamic Programming based C++ program to find minimum
+  number operations to convert str1 to str2
+*/
+
+#include <iostream>
+
+using namespace std;
+
+// Utility function to find minimum of three numbers 
+int min(int x, int y, int z) { 
+    return min(min(x, y), z); 
+}
+
+int EditDist(string str1, string str2, int m, int n) {
+
+    int dp[m+1][n+1];
+
+    // Base cases: when one string is empty (size 0), the only
+    // option is to insert/remove all characters of the other
+    // string, resulting in a number of operations equivalent
+    // to the size of this string
+    for (int i=0; i<m; i++)
+        dp[i][0] = i; // Remove all characters of str1
+    for (int j=0; j<n; j++)
+        dp[0][j] = j; // Insert all characters of str2
+
+    // Fill dp[][] (bottom up)
+    for (int i=1; i<=m; i++) {
+        for (int j=1; j<=n; j++) {
+            // If equal letters, cost is same as previous pair
+            if (str1[i-1] == str2[j-1]) 
+                dp[i][j] = dp[i-1][j-1];
+            // Otherwise get min cost of the possible operations
+            else
+                dp[i][j] = 1 + min(dp[i][j-1],    // Insert
+                                   dp[i-1][j],    // Remove
+                                   dp[i-1][j-1]); // Replace
+        }
+    }
+
+    return dp[m][n];
+}
+
+int main() {
+    string str1, str2;
+
+    cout << "Enter first string\n";
+    cin >> str1;
+    cout << "Enter second string\n";
+    cin >> str2;
+
+    cout << EditDist(str1, str2, str1.length(), str2.length());
+}