Problem: 2050E - Three Strings
Language: java

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

public class Main {
    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();
           int[][] f=new int[a.length()+1][b.length()+1];
            for (int i = 0; i < a.length(); i++) {
                f[i+1][0]=f[i][0]+(a.charAt(i)==c.charAt(i)?0:1);
            }
            for (int i = 0; i < b.length(); i++) {
                f[0][i+1]=f[0][i]+(b.charAt(i)==c.charAt(i)?0:1);
            }
            f[0][0]=0;
            for (int i = 1; i <= a.length(); i++) {
                for (int j = 1; j <= b.length(); j++) {
                    f[i][j]=Integer.MAX_VALUE;
                    f[i][j]=Math.min(f[i][j],f[i-1][j]+(a.charAt(i-1)==c.charAt(i+j-1)? 0 : 1));
                    f[i][j]=Math.min(f[i][j],f[i][j-1]+(b.charAt(j-1)==c.charAt(i+j-1)? 0 : 1));
                }
            }
            System.out.println(f[a.length()][b.length()]);
        }
    }
}

Solution 2 (runtime: 280 ms):
import java.util.*;

import java.lang.*;

import java.io.*;



public class Codeforces {

    public static void main(String[] args){

        FastReader fr = new FastReader();

        int tc = fr.nextInt();



        while (tc-- > 0) {

            solve(fr);

        }

    }





    private static void solve(FastReader fr) {

        String a = fr.next();

        String b = fr.next();

        String c = fr.next();

        int[][] dp = new int[a.length()+1][b.length()+1];



        for(int[] row : dp) Arrays.fill(row, -1);



        System.out.println(solve(a, b, c, 0, 0, 0, dp));

    }



    static int solve(String a, String b, String c, int i, int j, int k, int[][] dp) {

        if(k == c.length()) return 0;

        if(i > a.length() || j > b.length()) return (int)(1e7);

        boolean isAMatch = false;

        boolean isBMatch = false;



        if(dp[i][j] != -1) return dp[i][j];



        if(i < a.length() && a.charAt(i) == c.charAt(k)){

            isAMatch = true;

        }



        if(j < b.length() && b.charAt(j) == c.charAt(k)){

            isBMatch = true;

        }



        int ans1 = solve(a, b, c, i+1, j, k+1, dp) + (isAMatch ? 0 : 1);

        int ans2 = solve(a, b, c, i, j + 1, k+1, dp) + (isBMatch ? 0 : 1);



        return dp[i][j] = Math.min(ans1, ans2);

    }





    static int[] readIntArray(FastReader fr, int n){

        int[] arr = new int[n];



        for(int i = 0; i < n; i++){

            arr[i] = fr.nextInt();

        }



        return arr;

    }



    static class FastReader {

        BufferedReader br;

        StringTokenizer st;



        public FastReader() {

            br = new BufferedReader(

                    new InputStreamReader(System.in));

        }



        String next() {

            while (st == null || !st.hasMoreElements()) {

                try {

                    st = new StringTokenizer(br.readLine());

                } catch (IOException e) {

                    e.printStackTrace();

                }

            }

            return st.nextToken();

        }



        int nextInt() {

            return Integer.parseInt(next());

        }



        long nextLong() {

            return Long.parseLong(next());

        }



        double nextDouble() {

            return Double.parseDouble(next());

        }



        String nextLine() {

            String str = "";

            try {

                if (st.hasMoreTokens()) {

                    str = st.nextToken("\n");

                } else {

                    str = br.readLine();

                }

            } catch (IOException e) {

                e.printStackTrace();

            }

            return str;

        }

    }



}