给定大小为N的数组arr 。任务是找到数组的前一半( N / 2 )个元素和后一半( N – N / 2 )个元素的和。
例子:
Input : arr[] = {20, 30, 60, 10, 25, 15, 40}
Output : 110, 90
Sum of first N/2 elemets 20 + 30 + 60 is 110
Input : arr[] = {50, 35, 20, 15}
Output : 85, 35
方法:
将SumFirst和SumSecond初始化为0。遍历给定的数组,如果当前索引小于N / 2,则在SumFirst中添加元素,否则在SumSecond中添加元素。
下面是上述方法的实现:
C++
// C++ program to find the sum of the first half
// elements and second half elements of an array
#include
using namespace std;
// Function to find the sum of the first half
// elements and second half elements of an array
void sum_of_elements(int arr[], int n)
{
int sumfirst = 0, sumsecond = 0;
for (int i = 0; i < n; i++) {
// Add elements in first half sum
if (i < n / 2)
sumfirst += arr[i];
// Add elements in the second half sum
else
sumsecond += arr[i];
}
cout << "Sum of first half elements is " <<
sumfirst << endl;
cout << "Sum of second half elements is " <<
sumsecond << endl;
}
// Driver Code
int main()
{
int arr[] = { 20, 30, 60, 10, 25, 15, 40 };
int n = sizeof(arr) / sizeof(arr[0]);
// Function call
sum_of_elements(arr, n);
return 0;
}
Java
// Java program to count pairs
// whose sum divisible by 'K'
import java.util.*;
class GFG
{
public static void sum_of_elements(int []arr,
int n)
{
int sumfirst = 0, sumsecond = 0;
for (int i = 0; i < n; i++)
{
// Add elements in first half sum
if (i < n / 2)
{
sumfirst += arr[i];
}
// Add elements in the second half sum
else
{
sumsecond += arr[i];
}
}
System.out.println("Sum of first half elements is " +
sumfirst);
System.out.println("Sum of second half elements is " +
sumsecond);
}
// Driver code
public static void main(String[] args)
{
int []arr = { 20, 30, 60, 10, 25, 15, 40 };
int n = arr.length;
// Function call
sum_of_elements(arr, n);
}
}
// This code is contributed by Princi Singh
Python3
# Python3 program to find the sum of
# the first half elements and
# second half elements of an array
# Function to find the sum of
# the first half elements and
# second half elements of an array
def sum_of_elements(arr, n):
sumfirst = 0;
sumsecond = 0;
for i in range(n):
# Add elements in first half sum
if (i < n // 2):
sumfirst += arr[i];
# Add elements in the second half sum
else:
sumsecond += arr[i];
print("Sum of first half elements is",
sumfirst, end = "\n");
print("Sum of second half elements is",
sumsecond, end = "\n");
# Driver Code
arr = [20, 30, 60, 10, 25, 15, 40];
n = len(arr);
# Function call
sum_of_elements(arr, n);
# This code is contributed
# by Akanksha Rai
C#
// C# program to count pairs
// whose sum divisible by 'K'
using System;
class GFG
{
public static void sum_of_elements(int []arr,
int n)
{
int sumfirst = 0, sumsecond = 0;
for (int i = 0; i < n; i++)
{
// Add elements in first half sum
if (i < n / 2)
{
sumfirst += arr[i];
}
// Add elements in the second half sum
else
{
sumsecond += arr[i];
}
}
Console.WriteLine("Sum of first half elements is " +
sumfirst);
Console.WriteLine("Sum of second half elements is " +
sumsecond);
}
// Driver code
static public void Main ()
{
int []arr = { 20, 30, 60, 10, 25, 15, 40 };
int n = arr.Length;
// Function call
sum_of_elements(arr, n);
}
}
// This code is contributed by nidhiva
输出:
Sum of first half elements is 110
Sum of second half elements is 90
时间复杂度: O(N)
辅助空间: O(1)