Given a N x M matrix. The task is to print the sum of upper and lower triangular elements (i.e elements on the diagonal and the upper and lower elements).
Examples :
Input: {{6, 5, 4}, {1, 2, 5}, {7, 9, 7}}
Output:
Upper sum is 29
Lower sum is 32Input: {{1, 1, 1}, {2, 2, 2}, {3, 3, 3}}
Output:
Upper sum is 10
Lower sum is 14
Approach: To solve the problem follow the below approach
Traverse the matrix and calculate the sum for upper and lower triangles accordingly.
Below is the implementation of the above approach:
C++
// C++ program to calculate the sum // of upper and lower triangle #include <bits/stdc++.h> using namespace std;
// Function to calculate sum void sum(int mat[3][3], int r, int c)
{ int i, j;
int upper_sum = 0;
int lower_sum = 0;
// To calculate sum of upper triangle
for (i = 0; i < r; i++)
for (j = 0; j < c; j++) {
if (i <= j) {
upper_sum += mat[i][j];
}
}
printf("Upper sum is %d\n", upper_sum);
// To calculate sum of lower
for (i = 0; i < r; i++)
for (j = 0; j < c; j++) {
if (j <= i) {
lower_sum += mat[i][j];
}
}
printf("Lower sum is %d", lower_sum);
} // Driver function int main()
{ int r = 3;
int c = 3;
// Giving the matrix
int mat[3][3]
= { { 6, 5, 4 }, { 1, 2, 5 }, { 7, 9, 7 } };
// Function Call
sum(mat, r, c);
return 0;
} |
Java
// Java program to calculate the sum // of upper and lower triangle class GFG {
/*Function to calculate sum*/
static void sum(int mat[][], int r, int c)
{
int i, j;
int upper_sum = 0;
int lower_sum = 0;
/*Calculate sum of upper triangle*/
for (i = 0; i < r; i++)
for (j = 0; j < c; j++) {
if (i <= j) {
upper_sum += mat[i][j];
}
}
System.out.println("Upper sum is " + upper_sum);
/*Calculate sum of lower*/
for (i = 0; i < r; i++)
for (j = 0; j < c; j++) {
if (j <= i) {
lower_sum += mat[i][j];
}
}
System.out.print("Lower sum is " + lower_sum);
}
// Driver code
public static void main(String[] args)
{
int r = 3;
int c = 3;
/*Giving the matrix*/
int mat[][]
= { { 6, 5, 4 }, { 1, 2, 5 }, { 7, 9, 7 } };
/*Calling the function*/
sum(mat, r, c);
}
} // This code is contributed by Anant Agarwal. |
Python3
# Python3 program to calculate the sum # of upper and lower triangle # Function to calculate sum def Sum(mat, r, c):
i, j = 0, 0
upper_sum = 0
lower_sum = 0
# To calculate sum of upper triangle
for i in range(r):
for j in range(c):
if (i <= j):
upper_sum += mat[i][j]
print("Upper sum is ", upper_sum)
# To calculate sum of lower
for i in range(r):
for j in range(c):
if (j <= i):
lower_sum += mat[i][j]
print("Lower sum is ", lower_sum)
# Driver Code r = 3
c = 3
# Giving the matrix mat = [[6, 5, 4],
[1, 2, 5],
[7, 9, 7]]
# Function Call Sum(mat, r, c)
# This code is contributed by 29AjayKumar |
C#
// C# program to calculate the sum // of upper and lower triangle using System;
class GFG {
/*Function to calculate sum*/
static void sum(int[, ] mat, int r, int c)
{
int i, j;
int upper_sum = 0;
int lower_sum = 0;
/*Calculate sum of upper triangle*/
for (i = 0; i < r; i++)
for (j = 0; j < c; j++) {
if (i <= j) {
upper_sum += mat[i, j];
}
}
Console.WriteLine("Upper sum is " + upper_sum);
/*Calculate sum of lower*/
for (i = 0; i < r; i++)
for (j = 0; j < c; j++) {
if (j <= i) {
lower_sum += mat[i, j];
}
}
Console.Write("Lower sum is " + lower_sum);
}
// Driver code
public static void Main()
{
int r = 3;
int c = 3;
/*giving the matrix*/
int[, ] mat
= { { 6, 5, 4 }, { 1, 2, 5 }, { 7, 9, 7 } };
// Function Call
sum(mat, r, c);
}
} // This code is contributed by nitin mittal. |
PHP
<?php // PHP program to calculate the sum // of upper and lower triangle // Function to calculate sum function sum($mat, $r, $c)
{ $upper_sum = 0;
$lower_sum = 0;
/* To calculate sum of
upper triangle */
for ($i = 0; $i < $r; $i++)
for ($j = 0; $j < $c; $j++)
{
if ($i <= $j)
{
$upper_sum += $mat[$i][$j];
}
}
echo "Upper sum is ". $upper_sum."\n";
/* To calculate sum of lower */
for ($i = 0; $i < $r; $i++)
for ($j = 0; $j < $c; $j++)
{
if ($j <= $i)
{
$lower_sum += $mat[$i][$j];
}
}
echo "Lower sum is ". $lower_sum;
} // Driver Code
$r = 3;
$c = 3;
/*Giving the matrix*/
$mat = array(array(6, 5, 4),
array(1, 2, 5),
array(7, 9, 7));
//Function Call
sum($mat, $r, $c);
// This code is contributed by Sam007 ?> |
Javascript
<script> // Javascript program to calculate the sum // of upper and lower triangle /*function to calculate sum*/function sum(mat,r,c)
{ let i, j;
let upper_sum = 0;
let lower_sum = 0;
/*to calculate sum of upper triangle*/
for (i = 0; i < r; i++)
for (j = 0; j < c; j++) {
if (i <= j) {
upper_sum += mat[i][j];
}
}
document.write("Upper sum is "+ upper_sum+"<br/>");
/*to calculate sum of lower*/
for (i = 0; i < r; i++)
for (j = 0; j < c; j++) {
if (j <= i) {
lower_sum += mat[i][j];
}
}
document.write("Lower sum is "+lower_sum);
} /*driver function*/ let r = 3;
let c = 3;
/*giving the matrix*/
let mat = [[ 6, 5, 4 ],
[ 1, 2, 5 ],
[ 7, 9, 7 ]];
/*calling the function*/
sum(mat, r, c);
// This code contributed by Rajput-Ji </script> |
Output
Upper sum is 29 Lower sum is 32
Time Complexity: O(r * c), Where r and c represent the number of rows and columns of the given matrix.
Auxiliary Space: O(1), No extra space is required, so it is a constant.