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Write a program to Find sum of all elements above diagonal in matrix in java.
Sum of elements above diagonal = 2+3+4+7+8+5= 29
Logic behind finding sum of elements above diagonal is:
//Logic to calculate sum of elements above diagonal.
int sum=0;
for (int j = 1; j < columns; j++) {
for (int i=j-1 ; i>=0 ; i--) {
sum= sum + matrix[i][j];
}
}
Example/ Full Program/SourceCode to Find sum of elements above diagonal in matrix in java >
package matrix;
import java.util.Scanner;
/** Copyright (c), AnkitMittal JavaMadeSoEasy.com
Find sum of elements above diagonal in matrix in java*/
public class SumOfElementsAboveDiagonal {
public static void main(String...args) {
Scanner scanner = new Scanner(System.in);
System.out.print("Enter number of rows/columns in matrix : "); //rows and columns in matrix must be same.
int rows = scanner.nextInt();
int columns=rows;
int[][] matrix = new int[rows][rows];
System.out.println("Enter the elements in matrix :");
for (int i = 0; i < rows; i++) {
for (int j = 0; j < columns; j++) {
matrix[i][j] = scanner.nextInt();
}
}
//Logic to calculate sum of elements above diagonal.
int sum=0;
for (int j = 1; j < columns; j++) {
for (int i=j-1 ; i>=0 ; i--) {
sum= sum + matrix[i][j];
}
}
System.out.println("\nMatrix is : ");
for (int i = 0; i < rows; i++) {
for (int j = 0; j < columns; j++) {
System.out.print(matrix[i][j] + " ");
}
System.out.println();
}
System.out.println("sum of elements above diagonal is: "+sum);
}
}
/*OUTPUT
Enter number of rows/columns in matrix : 4
Enter the elements in matrix :
1
2
3
4
5
6
7
8
8
7
6
5
4
3
2
1
Matrix is :
1 2 3 4
5 6 7 8
8 7 6 5
4 3 2 1
sum of elements above diagonal is: 29
*/
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We Wrote a program to Find sum of all elements above diagonal in matrix in java.
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Labels:
Core Java
Matrix programs