面试题04. 二维数组中的查找

╰+哭是因爲堅強的太久メ 2023-07-18 03:16 2阅读 0赞

# 题目： #

[面试题04. 二维数组中的查找][04.]  
同：[240. 搜索二维矩阵 II][240. _ II]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p5eF9seQ_size_16_color_FFFFFF_t_70]

# 题解： #

## 1. 题解一： ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p5eF9seQ_size_16_color_FFFFFF_t_70 1]

## 2. 题解二： ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p5eF9seQ_size_16_color_FFFFFF_t_70 2]

# 代码： #

## 1. 代码一： ##

/** * 面试题04 */
    public class 面试题04 { 
    
        // 解法1：
        public static boolean findNumberIn2DArray(int[][] matrix, int target) { 
            for (int i = 0; i < matrix.length; i++) { 
                for (int j = 0; j < matrix[0].length; j++) { 
                    if (matrix[i][j] == target) { 
                        return true;
                    }
                }
            }
            return false;
        }
    
        public static void main(String[] args) { 
            int matrix[][] = {  {  1, 4, 7, 11, 15 }, {  2, 5, 8, 12, 19 }, {  3, 6, 9, 16, 22 }, {  10, 13, 14, 17, 24 },
                    {  18, 21, 23, 26, 30 } };
            int target1 = 5;
            int target2 = 20;
            boolean res1 = findNumberIn2DArray(matrix, target1);
            boolean res2 = findNumberIn2DArray(matrix, target2);
            System.out.println(res1 + " " + res2);
        }
    }

## 2. 代码二： ##

/** * 面试题04 */
    public class 面试题04 { 
    
        // 解法2：
        public static boolean findNumberIn2DArray(int[][] matrix, int target) { 
            if (matrix == null || matrix.length == 0 || matrix[0].length == 0) { 
                return false;
            }
            int i = 0;
            int j = matrix[0].length - 1;
            while (i < matrix.length && j >= 0) { 
                if (matrix[i][j] == target) { 
                    return true;
                } else if (matrix[i][j] < target) { 
                    i++;
                } else if (matrix[i][j] > target) { 
                    j--;
                }
            }
            return false;
        }
    
        public static void main(String[] args) { 
            int matrix[][] = {  {  1, 4, 7, 11, 15 }, {  2, 5, 8, 12, 19 }, {  3, 6, 9, 16, 22 }, {  10, 13, 14, 17, 24 },
                    {  18, 21, 23, 26, 30 } };
            int target1 = 5;
            int target2 = 20;
            boolean res1 = findNumberIn2DArray(matrix, target1);
            boolean res2 = findNumberIn2DArray(matrix, target2);
            System.out.println(res1 + " " + res2);
        }
    }

# 参考： #

1.  [面试题04. 二维数组中的查找][04. 1]

[04.]: https://leetcode-cn.com/problems/er-wei-shu-zu-zhong-de-cha-zhao-lcof/
[240. _ II]: https://leetcode-cn.com/problems/search-a-2d-matrix-ii/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p5eF9seQ_size_16_color_FFFFFF_t_70]: /images/20230528/16f2d57644f94c87b1ece504bcb9306e.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p5eF9seQ_size_16_color_FFFFFF_t_70 1]: /images/20230528/36c1a048479f40368c9cb3fab6d6c9eb.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p5eF9seQ_size_16_color_FFFFFF_t_70 2]: /images/20230528/f301f5fc6ff14b8e84085d5f388c5637.png
[04. 1]: https://leetcode-cn.com/problems/er-wei-shu-zu-zhong-de-cha-zhao-lcof/solution/mian-shi-ti-04-er-wei-shu-zu-zhong-de-cha-zhao-b-3/