java - 在二维数组中查找行的最大值和列的最小值

Question

我需要编写一个 java 代码，将二维数组作为矩阵并检查每一行和每一列，并找到行中最大值但列中最小值的数字。

例如，13 是列的最小值和行的最大值:

我写了代码，但我迷路了:

import java.util.Scanner;

public class maxmin {
    public static Scanner input = new Scanner(System.in);
    public static void main(String[] args) {
        System.out.println("enter matrix size ");
        int num = input.nextInt();
        int num1 = input.nextInt();

        maxMin(num, num1);
    }

    private static void maxMin(int num, int num1) {
        int max = 0;
        int min = 0;

        int[][] matrix = new int[num][num1];
        System.out.println("ENTER ARRAY NUMBERS");
        for (int i = 0; i < matrix.length; i++) {
            for (int j = 0; j < matrix[0].length; j++) {
                matrix[i][j] = input.nextInt();
            }
        }

        for (int i = 0; i < matrix.length; i++) {
            for (int j = 0; j < matrix[0].length; j++) {
                if (matrix[i][j] >= max) {
                    max = matrix[i][j];
                    for (int a = 0; a < matrix.length; a++) {
                        if (matrix[i][a] <= min) {
                            min = matrix[i][a];
                        }
                        if (max == min) {
                            System.out.println(max);
                        }
                    }
                }
            }
        }
    }
}

Answer 1

您可以使用 IntStream为此目的:

int[][] arr = {
        {1, 2, 3, 6, 5},
        {3, 2, 5, 6, 7},
        {5, 6, 7, 8, 9},
        {1, 3, 0, 2, 4}};

int num = Arrays
        // iterate over the nested arrays,
        // i.e. rows of the 2d array
        .stream(arr)
        // find maximum value of the row
        // return IntStream of maximums
        .mapToInt(row -> Arrays.stream(row)
                // maximum value of the row
                .max().orElse(Integer.MIN_VALUE))
        // find minimum value of row maximums
        .min().orElse(Integer.MIN_VALUE);

// output
System.out.println(num); // 4