Problem: 2050E - Three Strings
Language: java

Solution 1 (runtime: 343 ms):
import java.util.Arrays;
import java.util.Scanner;

public class ThreeStrings {
    public static void main(String[] args) {
        Scanner sc= new Scanner(System.in);
        int t= sc.nextInt();
        for (int i = 0; i < t; i++) {
            String a = sc.next();
            String b = sc.next();
            String c = sc.next();

            int lenA = a.length();
            int lenB = b.length();
            int lenC = c.length();

            long dp[][] = new long[lenA + 10][lenB + 10];

            for(long [] x : dp ) Arrays.fill( x , -1 );

            System.out.println(rec( 0 , 0 , dp , lenA , lenB , a , b, c));
        }
    }

    static long rec ( int x , int y , long dp[][] , int lenA , int lenB , String a , String b, String c){

        if ( x == lenA ){
            long add = 0;
            for(int i = y ; i < lenB ;i++){
                if ( b.charAt(i) != c.charAt( x + i )) add ++ ;
            }
            return add ;
        }
        if ( y == lenB ){
            long add = 0;
            for(int i = x ; i < lenA ;i++){
                if ( a.charAt(i) != c.charAt( i + y )) add ++ ;
            }
            return add ;
        }
        if ( dp[x][y] != -1) return dp[x][y];
        long ans1 = (a.charAt( x ) == c.charAt( x + y ) ? 0 : 1 ) + rec( x + 1 , y , dp , lenA , lenB , a, b, c);
        long ans2 = (b.charAt( y ) == c.charAt( x + y ) ? 0 : 1 ) + rec( x  , y + 1 , dp , lenA , lenB , a, b, c);

        return dp[x][y] = Math.min(ans1 , ans2);
    }
}


Solution 2 (runtime: 374 ms):
import java.util.*;

public class Solution {
    static int dp[][];
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int t = sc.nextInt();

        while(t-->0){
            String a=sc.next();
            String b=sc.next();
            String c=sc.next();
            dp=new int[a.length()+1][b.length()+1];

            for(int i=0;i<dp.length;i++){
                Arrays.fill(dp[i],-1);
            }
            System.out.println(solve(a,b,c,0,0,0));

        }
    }
    public static int solve(String a,String b,String c,int i,int j,int k){
        if(i==a.length() || j==b.length()){
            return calc(a,b,c,i,j,k);
        }
        if(dp[i][j]!=-1) return dp[i][j];
        if(c.charAt(k)==a.charAt(i) && c.charAt(k)==b.charAt(j)){
            return dp[i][j]=Math.min(solve(a,b,c,i+1,j,k+1),solve(a,b,c,i,j+1,k+1));

        }
        else if(c.charAt(k)==a.charAt(i) ){
            return dp[i][j]=Math.min(solve(a,b,c,i+1,j,k+1),1+solve(a,b,c,i,j+1,k+1));
        }
        else if(c.charAt(k)==b.charAt(j)){
            return dp[i][j]=Math.min(solve(a,b,c,i,j+1,k+1),1+solve(a,b,c,i+1,j,k+1));
        }
        else return dp[i][j]=1+Math.min(solve(a,b,c,i+1,j,k+1),solve(a,b,c,i,j+1,k+1));
    }

    public static int calc(String a,String b,String c,int i,int j,int k){
        int count=0;
        if(i==a.length()){
            while(j<b.length()){
                if(b.charAt(j)!=c.charAt(k)){
                    count++;
                }
                k++;
                j++;
            }

        }
        else{
            while(i<a.length()){
                if(a.charAt(i)!=c.charAt(k)){
                    count++;
                }
                i++;
                k++;
            }
        }
        return count;
    }
}