poj2030

递推

import java.math.BigInteger;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner cin = new Scanner(System.in);
        while (true) {
            int n, m;
            m = cin.nextInt();
            n = cin.nextInt();
            if (n == 0 && m == 0)
                return;
            String[] map = new String[n];
            for (int i = 0; i < n; i++)
                map[i] = cin.next();
            BigInteger[][] f = new BigInteger[n][m];
            for (int i = 0; i < n; i++)
                for (int j = 0; j < m; j++)
                    if (map[i].charAt(j) >= '0' && map[i].charAt(j) <= '9') {
                        BigInteger temp = BigInteger.valueOf((int) (map[i]
                                .charAt(j) - '0'));
                        f[i][j] = temp;
                        if (j - 1 >= 0) {
                            BigInteger a = f[i][j - 1].multiply(
                                    BigInteger.valueOf(10)).add(temp);
                            if (f[i][j].compareTo(a) < 0)
                                f[i][j] = a;
                        }
                        if (i - 1 >= 0) {
                            BigInteger a = f[i - 1][j].multiply(BigInteger.valueOf(10))
                                    .add(temp);
                            if (f[i][j].compareTo(a) < 0)
                                f[i][j] = a;
                        }
//                        System.out.println(i + " " + j + " " + f[i][j]);
                    } else
                        f[i][j] = BigInteger.ZERO;
            BigInteger ans = BigInteger.ZERO;
            for (int i = 0; i < n; i++)
                for (int j = 0; j < m; j++)
                    if (ans.compareTo(f[i][j]) < 0)
                        ans = f[i][j];
            System.out.println(ans);
        }
    }
}