第四届蓝桥杯--剪格子

import java.util.Scanner;
public class Main7 {
static int m, n;
static int[][] num;
static String s = "";
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
m = input.nextInt();
n = input.nextInt();
num = new int
[m];
int zh = 0;
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
num[i][j] = input.nextInt();
zh += num[i][j];
}
}
if (zh % 2 == 0) {
int sum = zh / 2;
f(num[0][0] + ";", sum - num[0][0], 0, 0, "0,0 ");
}
if (s.length() > 0)
System.out.println(s.split(";").length);
else
System.out.println(0);
}

public static void f(String str, int sum, int x, int y, String xy) {
if (sum == 0) {
if (s.equals(""))
s = str;
else if (s.length() > str.length())
s = str;
return;
}
if (sum < 0)
return;
if (x < m - 1 && !xy.contains((x + 1) + "," + y + " "))
f(str + num[y][x + 1] + ";", sum - num[y][x + 1], x + 1, y, xy
+ (x + 1) + "," + y + " ");
if (x > 0 && !xy.contains((x - 1) + "," + y + " "))
f(str + num[y][x - 1] + ";", sum - num[y][x - 1], x - 1, y, xy
+ (x - 1) + "," + y + " ");
if (y < n - 1 && !xy.contains(x + "," + (y + 1) + " "))
f(str + num[y + 1][x] + ";", sum - num[y + 1][x], x, y + 1, xy + x
+ "," + (y + 1) + " ");
if (y > 0 && !xy.contains(x + "," + (y - 1) + " "))
f(str + num[y - 1][x] + ";", sum - num[y - 1][x], x, y - 1, xy + x
+ "," + (y - 1) + " ");
}
}