Given N*M matrix find the sum of the elements of the matrix without the element specified by its position
Examples:
Input : mat[] = {{1 2 4},
{5 6 8}}
cell = (0 2)
Output :22
We need to find sum of all elements
except mat[0][2].
Input : mat[][] = {{5 6 2 3}, {2 3 1 8}, {9 6 5 2}}
cell = (1 2)
Output :51
Approach 1: A simple solution is to traverse through the matrix. For every visited cell, check if it is the cell to be ignored.
C++
// C++ program to find sum // of matrix except cell (x, y)#include<bits/stdc++.h>using namespace std;// Dimension of input matrix# define R 2# define C 3// Returns sum of arr[][]// except cell arr[x][y]int calcSum(int arr[R][C], int x, int y){ int sum = 0; for (int i = 0; i < R; i++) { for (int j = 0; j < C; j++) { if (i != x || j != y) sum = sum + arr[i][j]; } } return sum;}// Driver codeint main(){ int x = 0, y = 2; int arr[R][C] = {1, 2, 4, 5, 6, 8 }; cout << calcSum(arr, x, y);}// This code is contributed // by ChitraNayal |
Java
// Java program to find sum of matrix except // cell (x, y)class Matrix { // Returns sum of arr[][] except cell arr[x][y] static int calcSum(int[][] arr, int x, int y) { int sum = 0; for (int i = 0; i < arr.length; i++) { for (int j = 0; j < arr[i].length; j++) { if (i != x || j != y) sum = sum + arr[i][j]; } } return sum; } public static void main(String[] args) { int x = 0, y = 2; int[][] arr = { { 1, 2, 4 }, { 5, 6, 8 }, }; System.out.println(calcSum(arr, x, y)); }} |
C#
// C# program to find sum // of matrix except cell (x, y)using System;class GFG { // Returns sum of arr[,] // except cell arr[x][y] static int calcSum(int[,] arr, int x, int y) { int sum = 0; for (int i = 0; i < arr.GetLength(0); i++) { for (int j = 0; j < arr.GetLength(1); j++) { if (i != x || j != y) sum = sum + arr[i, j]; } } return sum; } // Driver Code public static void Main() { int x = 0, y = 2; int[,] arr = {{ 1, 2, 4 }, { 5, 6, 8 }}; Console.Write(calcSum(arr, x, y)); }}// This code is contributed// by ChitraNayal |
Python 3
# Python 3 program to find # sum of matrix except cell (x, y)# Returns sum of arr[][]# except cell arr[x][y]def calcSum(arr, x, y): s = 0 for i in range(R): for j in range(C): if (i != x or j != y): s = s + arr[i][j]; return s;# Driver codex = 0y = 2arr = [[ 1, 2, 4 ], [ 5, 6, 8 ]]R = 2C = 3print(calcSum(arr, x, y))# This code is contributed # by ChitraNayal |
PHP
<?php // PHP program to find // sum of matrix except // cell (x, y)$R = 2;$C = 3;// Returns sum of arr[][]// except cell arr[x][y]function calcSum(&$arr, $x, $y){ global $R,$C; $sum = 0; for ($i = 0; $i < $R; $i++) { for ($j = 0; $j < $C; $j++) { if ($i != $x || $j != $y) $sum = $sum + $arr[$i][$j]; } } return $sum;}// Driver code$x = 0;$y = 2;$arr = array(array(1, 2, 4), array(5, 6, 8)); echo (calcSum($arr, $x, $y)); // This code is contributed // by ChitraNayal?> |
Javascript
<script>// Javascript program to find sum of matrix except // cell (x, y) // Returns sum of arr[][] except cell arr[x][y] function calcSum(arr,x,y) { let sum = 0; for (let i = 0; i < arr.length; i++) { for (let j = 0; j < arr[i].length; j++) { if (i != x || j != y) sum = sum + arr[i][j]; } } return sum; } let x = 0, y = 2; let arr=[[1, 2, 4],[5, 6, 8 ]]; document.write(calcSum(arr, x, y)); // This code is contributed by rag2127</script> |
Output
22
Time Complexity: O(R*C), where R and C are rows and columns of the given matrix|
Auxiliary Space: O(1)
Approach 2: The above solution causes an extra comparison for every matrix item. A better solution is to first find the overall sum, then subtract the given cell.
C++
// C++ program to find sum // of matrix except cell (x, y)#include<bits/stdc++.h>using namespace std;#define R 2#define C 3// Returns sum of arr[][] // except cell arr[x][y]int calcSum(int arr[R][C], int x, int y){ int sum = 0; for (int i = 0; i < R; i++) for (int j = 0; j < C; j++) sum = sum + arr[i][j]; return sum - arr[x][y];}// Driver codeint main(){ int x = 0, y = 2; int arr[R][C]= {1, 2, 4 , 5, 6, 8 }; cout << (calcSum(arr, x, y));}// This code is contributed// by ChitraNayal |
Java
// Java program to find sum of matrix except // cell (x, y)class Matrix { // Returns sum of arr[][] except cell arr[x][y] static int calcSum(int[][] arr, int x, int y) { int sum = 0; for (int i = 0; i < arr.length; i++) for (int j = 0; j < arr[i].length; j++) sum = sum + arr[i][j]; return sum - arr[x][y]; } public static void main(String[] args) { int x = 0, y = 2; int[][] arr = { { 1, 2, 4 }, { 5, 6, 8 }, }; System.out.println(calcSum(arr, x, y)); }} |
C#
// C# program to find sum // of matrix except cell (x, y)using System;class GFG { // Returns sum of arr[,] // except cell arr[x,y] static int calcSum(int[,] arr, int x, int y) { int sum = 0; for (int i = 0; i < arr.GetLength(0); i++) for (int j = 0; j < arr.GetLength(1); j++) sum = sum + arr[i, j]; return sum - arr[x, y]; } // Driver code public static void Main() { int x = 0, y = 2; int[,] arr = {{ 1, 2, 4 }, { 5, 6, 8 }}; Console.Write(calcSum(arr, x, y)); }}// This code is contributed// by ChitraNayal |
Python 3
# Python 3 program to find # sum of matrix except cell (x, y)# Returns sum of arr[][] # except cell arr[x][y]def calcSum( arr, x, y): s = 0 for i in range(R): for j in range(C): s = s + arr[i][j] return s - arr[x][y]# Driver codex = 0y = 2R = 2C = 3arr = [[1, 2, 4 ], [5, 6, 8 ]]print (calcSum(arr, x, y))# This code is contributed # by ChitraNayal |
PHP
<?php // PHP program to find sum // of matrix except cell (x, y)$R = 2;$C = 3;// Returns sum of $arr[][] // except cell $arr[$x][$y]function calcSum(&$arr, $x, $y){ global $R,$C; $sum = 0; for ($i = 0; $i < $R; $i++) for ($j = 0; $j < $C; $j++) $sum = $sum + $arr[$i][$j]; return $sum - $arr[$x][$y];}// Driver code$x = 0;$y = 2;$arr= array(array(1, 2, 4 ), array(5, 6, 8 ));echo (calcSum($arr, $x, $y));// This code is contributed// by ChitraNayal?> |
Javascript
<script>// Javascript program to find sum of matrix except// cell (x, y) // Returns sum of arr[][] except cell arr[x][y] function calcSum(arr,x,y) { let sum = 0; for (let i = 0; i < arr.length; i++) for (let j = 0; j < arr[i].length; j++) sum = sum + arr[i][j]; return sum - arr[x][y]; } let x = 0, y = 2; let arr = [[1, 2, 4 ], [5, 6, 8 ]]; document.write(calcSum(arr, x, y)); // This code is contributed by avanitrachhadiya2155</script> |
Output
22
Time Complexity: O(R*C) where R and C are rows and columns of a given matrix|
Auxiliary Space: O(1)
Another Approach:
Approach;
Initialize a variable “totalSum” to 0 to keep track of the total sum of all elements in the matrix.
Iterate through each element in the matrix and add its value to “totalSum”.
Iterate through each element in the matrix again, and for each element, subtract its value from “totalSum” if it is not the element to be excluded.
Return the value of “totalSum” as the sum of all elements in the matrix except the excluded element.
C
#include <stdio.h>// Function to find the sum of all elements in the matrix except the excluded elementint matrixSumExceptOne(int matrix[][3], int rows, int cols, int excludedRow, int excludedCol) { // Initialize totalSum to 0 int totalSum = 0; // Iterate through each element in the matrix and add its value to totalSum for (int i = 0; i < rows; i++) { for (int j = 0; j < cols; j++) { totalSum += matrix[i][j]; } } // Iterate through each element in the matrix again, and for each element, // subtract its value from totalSum if it is not the excluded element for (int i = 0; i < rows; i++) { for (int j = 0; j < cols; j++) { if (i == excludedRow && j == excludedCol) { totalSum -= matrix[i][j]; } } } // Return the value of totalSum as the sum of all elements in the matrix except the excluded element return totalSum;}// Driver codeint main() { // Sample input int matrix[3][3] = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}; int excludedRow = 1, excludedCol = 1; int rows = 3, cols = 3; // Find the sum of all elements in the matrix except the excluded element int sum = matrixSumExceptOne(matrix, rows, cols, excludedRow, excludedCol); // Print the result printf("The sum of all elements in the matrix except the element at row %d, column %d is %d\n", excludedRow, excludedCol, sum); return 0;} |
C++
#include <iostream>using namespace std;// Function to find the sum of all elements in the matrix except the excluded elementint matrixSumExceptOne(int matrix[][3], int rows, int cols, int excludedRow, int excludedCol) { // Initialize totalSum to 0 int totalSum = 0; // Iterate through each element in the matrix and add its value to totalSum for (int i = 0; i < rows; i++) { for (int j = 0; j < cols; j++) { totalSum += matrix[i][j]; } } // Iterate through each element in the matrix again, and for each element, // subtract its value from totalSum if it is not the excluded element for (int i = 0; i < rows; i++) { for (int j = 0; j < cols; j++) { if (i == excludedRow && j == excludedCol) { totalSum -= matrix[i][j]; } } } // Return the value of totalSum as the sum of all elements in the matrix except the excluded element return totalSum;}// Driver codeint main() { // Sample input int matrix[3][3] = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}; int excludedRow = 1, excludedCol = 1; int rows = 3, cols = 3; // Find the sum of all elements in the matrix except the excluded element int sum = matrixSumExceptOne(matrix, rows, cols, excludedRow, excludedCol); // Print the result cout << "The sum of all elements in the matrix except the element at row " << excludedRow << ", column " << excludedCol << " is " << sum << endl; return 0;} |
Java
import java.util.*;public class MatrixSumExceptOne{ // Function to find the sum of all elements // in the matrix except the excluded element public static int matrixSumExceptOne(int[][] matrix, int rows, int cols, int excludedRow, int excludedCol) { // Initialize totalSum to 0 int totalSum = 0; // Iterate through each element in // the matrix and add its value to totalSum for (int i = 0; i < rows; i++) { for (int j = 0; j < cols; j++) { totalSum += matrix[i][j]; } } // Iterate through each element in the matrix again, and for each element, // subtract its value from totalSum if it is not the excluded element for (int i = 0; i < rows; i++) { for (int j = 0; j < cols; j++) { if (i == excludedRow && j == excludedCol) { totalSum -= matrix[i][j]; } } } // Return the value of totalSum as the sum of // all elements in the matrix except the excluded element return totalSum; } // Driver code public static void main(String[] args) { // Sample input int[][] matrix = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}; int excludedRow = 1, excludedCol = 1; int rows = 3, cols = 3; // Find the sum of all elements in the matrix except the excluded element int sum = matrixSumExceptOne(matrix, rows, cols, excludedRow, excludedCol); // Print the result System.out.println("The sum of all elements in the matrix except the element at row " + excludedRow + ", column " + excludedCol + " is " + sum); }}// This code is contributed by Sundaram. |
Python3
def matrix_sum_except_one(matrix, rows, cols, excluded_row, excluded_col): # Initialize total_sum to 0 total_sum = 0 # Iterate through each element in the matrix and add its value to total_sum for i in range(rows): for j in range(cols): total_sum += matrix[i][j] # Iterate through each element in the matrix again, and for each element, # subtract its value from total_sum if it is not the excluded element for i in range(rows): for j in range(cols): if i == excluded_row and j == excluded_col: total_sum -= matrix[i][j] # Return the value of total_sum as the sum of all elements in the matrix except the excluded element return total_sum# Sample inputmatrix = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]excluded_row = 1excluded_col = 1rows = 3cols = 3# Find the sum of all elements in the matrix except the excluded elementsum = matrix_sum_except_one(matrix, rows, cols, excluded_row, excluded_col)# Print the resultprint("The sum of all elements in the matrix except the element at row", excluded_row, "column", excluded_col, "is", sum) |
C#
using System;class MatrixSumExceptOneClass{ // Function to find the sum of all elements // in the matrix except the excluded element public static int MatrixSumExceptOne(int[,] matrix, int rows, int cols, int excludedRow, int excludedCol) { // Initialize totalSum to 0 int totalSum = 0; // Iterate through each element in // the matrix and add its value to totalSum for (int i = 0; i < rows; i++) { for (int j = 0; j < cols; j++) { totalSum += matrix[i, j]; } } // Iterate through each element in the matrix again, and for each element, // subtract its value from totalSum if it is not the excluded element for (int i = 0; i < rows; i++) { for (int j = 0; j < cols; j++) { if (i == excludedRow && j == excludedCol) { totalSum -= matrix[i, j]; } } } // Return the value of totalSum as the sum of // all elements in the matrix except the excluded element return totalSum; } // Driver code static void Main(string[] args) { // Sample input int[,] matrix = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 } }; int excludedRow = 1, excludedCol = 1; int rows = 3, cols = 3; // Find the sum of all elements in the matrix except the excluded element int sum = MatrixSumExceptOne(matrix, rows, cols, excludedRow, excludedCol); // Print the result Console.WriteLine("The sum of all elements in the matrix except the element at row " + excludedRow + ", column " + excludedCol + " is " + sum); }} |
Javascript
// Function to find the sum of all elements in the matrix except the excluded elementfunction matrixSumExceptOne(matrix, rows, cols, excludedRow, excludedCol) { // Initialize totalSum to 0 let totalSum = 0; // Iterate through each element in the matrix and add its value to totalSum for (let i = 0; i < rows; i++) { for (let j = 0; j < cols; j++) { totalSum += matrix[i][j]; } } // Iterate through each element in the matrix again, and for each element, // subtract its value from totalSum if it is not the excluded element for (let i = 0; i < rows; i++) { for (let j = 0; j < cols; j++) { if (i === excludedRow && j === excludedCol) { totalSum -= matrix[i][j]; } } } // Return the value of totalSum as the sum of all elements in the matrix except the excluded element return totalSum;}// Driver code// Sample inputconst matrix = [[1, 2, 3], [4, 5, 6], [7, 8, 9]];const excludedRow = 1, excludedCol = 1;const rows = 3, cols = 3;// Find the sum of all elements in the matrix except the excluded elementconst sum = matrixSumExceptOne(matrix, rows, cols, excludedRow, excludedCol);// Print the resultconsole.log(`The sum of all elements in the matrix except the element at row ${excludedRow}, column ${excludedCol} is ${sum}`); |
Output
The sum of all elements in the matrix except the element at row 1, column 1 is 40
time complexity of O(N*M), Where N is the number of rows and M is the number of columns in the matrix
space complexity of O(1)
Feeling lost in the world of random DSA topics, wasting time without progress? It’s time for a change! Join our DSA course, where we’ll guide you on an exciting journey to master DSA efficiently and on schedule.
Ready to dive in? Explore our Free Demo Content and join our DSA course, trusted by over 100,000 neveropen!
Ready to dive in? Explore our Free Demo Content and join our DSA course, trusted by over 100,000 neveropen!
