算法(如何查找矩阵中每一列的最大元素())

本文概述

  • C ++
  • Java
  • Python3
  • C#
  • 的PHP
【算法(如何查找矩阵中每一列的最大元素())】给定一个矩阵, 任务是找到每一列的最大元素。
例子:
Input:[1, 2, 3] [1, 4, 9] [76, 34, 21]Output: 76 34 21Input: [1, 2, 3, 21] [12, 1, 65, 9] [1, 56, 34, 2] Output: 12 56 65 21

方法:
这个想法是为no_of_cols运行循环。检查列中的每个元素并查找最大元素。最后, 打印元素。
下面是上述方法的实现:
C ++
// C++ program to find the maximum // element of each column. #include < bits/stdc++.h> using namespace std; const int MAX = 100; // Function to find the maximum // element of each column. void largestInColumn( int mat[][MAX], int rows, int cols) { for ( int i = 0; i < cols; i++) { // initialize the maximum element // with 0 int maxm = mat[0][i]; // Run the inner loop for rows for ( int j = 1; j < rows; j++) { // check if any element is greater // than the maximum element // of the column and replace it if (mat[j][i] > maxm) maxm = mat[j][i]; }// print the largest element of the column cout < < maxm < < endl; } }// Driver code int main() { int n = 4, m = 4; int mat[][MAX] = { { 3, 4, 1, 8 }, { 1, 4, 9, 11 }, { 76, 34, 21, 1 }, { 2, 1, 4, 5 } }; largestInColumn(mat, n, m); return 0; }

Java
// Java program to find maximum // element of each column in a matrix public class GFG {// Function to find the maximum // element of each column. public static void largestInColumn( int cols, int [][] arr) {for ( int i = 0 ; i < cols; i++) {// Initialize max to 0 at beginning // of finding max element of each column int maxm = arr[ 0 ][i]; for ( int j = 1 ; j < arr[i].length; j++) if (arr[j][i] > maxm) maxm = arr[j][i]; System.out.println(maxm); } }// Driver code public static void main(String[] args) { int [][] arr = new int [][] { { 3 , 4 , 1 , 8 }, { 1 , 4 , 9 , 11 }, { 76 , 34 , 21 , 1 }, { 2 , 1 , 4 , 5 } }; // Calling the function largestInColumn( 4 , arr); } }

Python3
# Python3 program to find the maximum # element of each column MAX = 100# function to find the maximum # elements of each column def largestInColumn(mat, rows, cols): for i in range (cols):# initialize the maximum element with 0 maxm = mat[ 0 ][i] # run the inner loop for news for j in range (rows):# check if any elements is greater # than the maximum elements # of the cloumn and replace it if mat[j][i] > maxm: maxm = mat[j][i]# print the largest element # of the column print (maxm)# Driver code n, m = 4 , 4 mat = [[ 3 , 4 , 1 , 8 ], [ 1 , 4 , 9 , 11 ], [ 76 , 34 , 21 , 1 ], [ 2 , 1 , 4 , 5 ]]largestInColumn(mat, n, m); # This code is contributed # by Mohit kumar 29 (IIIT gwalior)

C#
// C# program to find maximum // element of each column in a matrix using System; class GFG {// Function to find the maximum // element of each column. public static void largestInColumn( int cols, int [, ] arr) { for ( int i = 0; i < cols; i++) {// Initialize max to 0 at beginning // of finding max element of each column int maxm = arr[0, i]; for ( int j = 1; j < arr.GetLength(0); j++) if (arr[j, i] > maxm) maxm = arr[j, i]; Console.WriteLine(maxm); } }// Driver code public static void Main() { int [, ] arr = new int [, ] { { 3, 4, 1, 8 }, { 1, 4, 9, 11 }, { 76, 34, 21, 1 }, { 2, 1, 4, 5 } }; // Calling the function largestInColumn(4, arr); } }// This code is contributed // by Akanksha Rai

的PHP
< ?php // PHP program to find the maximum // element of each column. $MAX = 100; // Function to find the maximum // element of each column. function largestInColumn( $mat , $rows , $cols ) { for ( $i = 0; $i < $cols ; $i ++) { // initialize the maximum element // with 0 $maxm = $mat [0][ $i ]; // Run the inner loop for rows for ( $j = 1; $j < $rows ; $j ++) { // check if any element is greater // than the maximum element // of the column and replace it if ( $mat [ $j ][ $i ] > $maxm ) $maxm = $mat [ $j ][ $i ]; } // print the largest element // of the column echo $maxm , "\n" ; } } // Driver code $n = 4; $m = 4; $mat = array ( array ( 3, 4, 1, 8 ), array ( 1, 4, 9, 11 ), array ( 76, 34, 21, 1 ), array ( 2, 1, 4, 5 )); largestInColumn( $mat , $n , $m ); // This code is contributed by Sach_Code ?>

输出如下:
76 34 21 11

时间复杂度:O(n * m), 这里n是矩阵的行数, m是矩阵的列数。

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