Create editDistance.cpp

20. Dynamic Programming/editDistance.cpp

@@ -0,0 +1,27 @@
+class Solution {
+public:    
+    int minDistance(string s1, string s2) {
+        int n = s1.size();
+        int m = s2.size();
+        // vector<vector<int>> dp(n+1, vector<int>(m+1, -1));
+        vector<int> prev(m+1, -1), curr(m+1, -1);
+
+        // for(int i = 0; i <= n; i++) dp[i][0] = i; //Covered in the nested for
+        for(int j = 0; j <= m; j++) prev[j] = j;
+
+        for(int i = 1; i<=n; i++){
+            curr[0] = i;
+            for(int j = 1; j<=m; j++){
+                if(s1[i-1] == s2[j-1]) curr[j] = 0 + prev[j-1] ;
+                else{
+                    curr[j] = 1 + min(prev[j], //delete
+                                    min(curr[j-1], //insert
+                                        prev[j-1])); //replace
+                }
+            }
+            prev = curr;
+        }
+
+        return prev[m];
+    }
+};