#feat:leetcode p1594题题解

src/leetcode/p1594/Solution.java

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+package leetcode.p1594;
+
+/**
+ * @ProjectName: LeetCode
+ * @FileName: Solution
+ * @Author: 杨逸
+ * @Data:2026/3/23 14:13
+ * @Description: https://leetcode.cn/problems/maximum-non-negative-product-in-a-matrix/
+ * 1594. 矩阵的最大非负积
+ */
+public class Solution {
+    private final static int MOD = (int)1e9 + 7;
+    private long[][][] dp;
+    public int maxProductPath(int[][] grid) {
+        /**
+         * 因需要考虑负负得正,所有需要记录最大值和最小值
+         */
+        dp = new long[grid.length][grid[0].length][2];
+        for (long[][] longs : dp) {
+            for (long[] aLong : longs) {
+                aLong[0]  = Long.MIN_VALUE;
+                aLong[1]  = Long.MIN_VALUE;
+            }
+        }
+        long[] ans = dfs(grid.length - 1, grid[0].length - 1, grid);
+        long res = ans[1] < 0 ? -1 : ans[1] % MOD;
+        return (int)res;
+    }
+
+    private long[] dfs(int x, int y, int[][] grid) {
+        if (x ==0 && y == 0) {
+            int v = grid[x][y];
+            return new long[]{v, v};
+        }
+
+        long current[] = dp[x][y];
+        if (current[1] != Long.MIN_VALUE) {
+            return current;
+        }
+        long min = Long.MAX_VALUE,max  = Long.MIN_VALUE;
+        if (x>0) {
+            long[] dfs = dfs(x - 1, y, grid);
+            min = Math.min(min,dfs[0] * grid[x][y]);
+            min = Math.min(min,dfs[1] * grid[x][y]);
+            max = Math.max(max,dfs[0] * grid[x][y]);
+            max = Math.max(max,dfs[1] * grid[x][y]);
+        }
+        if (y>0) {
+            long[] dfs = dfs(x, y - 1, grid);
+            min = Math.min(min,dfs[0] * grid[x][y]);
+            min = Math.min(min,dfs[1] * grid[x][y]);
+            max = Math.max(max,dfs[0] * grid[x][y]);
+            max = Math.max(max,dfs[1] * grid[x][y]);
+        }
+        current[0] = min;
+        current[1] = max;
+            return current;
+    }
+}

src/leetcode/p1594/SolutionTest.java

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+package leetcode.p1594;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import java.util.Arrays;
+import java.util.Collection;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @ProjectName: LeetCode
+ * @FileName: SolutionTest
+ * @Author: 杨逸
+ * @Data:2026/3/23 14:20
+ * @Description:
+ */
+@RunWith(Parameterized.class)
+public class SolutionTest {
+    public static final Solution solution = new Solution();
+    private final int[][] grid;
+    private final int expected;
+    public SolutionTest(int[][] grid, int expected) {
+        this.grid = grid;
+        this.expected = expected;
+    }
+    @Parameterized.Parameters
+    public static Collection<Object[]> data() {
+        return Arrays.asList(new Object[][]{
+            {new int[][]{{-1,-2,-3},{-2,-3,-3},{-3,-3,-2}},-1},
+            {new int[][]{{1,-2,1},{1,-2,1},{3,-4,1}},8},
+            {new int[][]{{1,3},{0,-4}},0},
+        });
+    }
+    @Test
+    public void maxProductPath() {
+        assertEquals(expected, solution.maxProductPath(grid));
+    }
+}