Sum of rows#9894

Sum of rows (Editorial)

Declare an array $s u m$ , where $s u m [i]$ will contain the sum of the elements in the $i$ -th row. For each value of $i$ , calculate $s u m [i]$ .

Example

Let's calculate the sums of the elements in each row of the matrix.

Algorithm implementation

Declare the arrays. Store the sum of the elements in the $i$ -th row in $s u m [i]$ .

int m[101][101], sum[101];

Read the input data.

scanf("%d", &n);
for (i = 1; i <= n; i++)
for (j = 1; j <= n; j++)
  scanf("%d", &m[i][j]);

For each value of $i$ , calculate the sum of the elements in the $i$ -th row and store it in $s u m [i]$ .

for (i = 1; i <= n; i++)
for (j = 1; j <= n; j++)
  sum[i] += m[i][j];

Print the resulting sums.

for (i = 1; i <= n; i++)
  printf("%d\n", sum[i]);

Java implementation

import java.util.*;

public class Main 
{
  public static void main(String[] args) 
  {
    Scanner con = new Scanner(System.in);
    int n = con.nextInt();

    int m[][] = new int[n][n];
    int sum[] = new int[n];

    for (int i = 0; i < n; i++)
    for (int j = 0; j < n; j++) 
    {
      m[i][j] = con.nextInt();
      sum[i] += m[i][j];
    }

    for (int i = 0; i < n; i++)
      System.out.println(sum[i]);
    con.close();
  }
}

Java

Python implementation

Read the size of the array $n$ .

n = int(input())

Read the input matrix.

m = [[] for _ in range(n)]
for i in range(n):
  m[i] = list(map(int, input().split()))

Calculate the sums of the elements in each row of the two-dimensional array.

res = [0] * n
for i in range(n):
   res[i] = sum(m[i])

Print the resulting sums.

for i in range(n):
  print(res[i])

Python implementation – on the fly

Read the size of the array $n$ .

n = int(input())

Read the input matrix.

for i in range(n):

Read a row of the matrix and print the sum of its elements.

  lst = list(map(int, input().split()))
  print(sum(lst))