Editorial

The problem can be solved both with and without an array. Sequentially read the numbers and increment each non-negative element by $2$ .

Algorithm implementation

Read the input value of $n$ .

scanf("%d",&n);

Sequentially read $n$ integers.

for (i = 0; i < n; i++)
{
  scanf("%d",&val);

If the number $v a l$ is non-negative, increase it by $2$ .

  if (val >= 0) val +=2;

Print the number $v a l$ after the modification.

  printf("%d ",val);
}
printf("\n");

Algorithm implementation — array

Declare an array.

int m[101];

Read the input data.

scanf("%d",&n);
for (i = 0; i < n; i++)
  scanf("%d",&m[i]);

Iterate through the elements of an array. Increase each non-negative element by $2$ .

for (i = 0; i < n; i++)
  if (m[i] >= 0) m[i] = m[i] + 2;

Print the answer — the resulting array.

for (i = 0; i < n; i++)
  printf("%d ",m[i]);
printf("\n");

Algorithm implementation — vector, push_back

Read the input data.

scanf("%d",&n);
for (i = 0; i < n; i++)
{
  scanf("%d",&val);
  m.push_back(val);
}

Iterate through the elements of an array. Increase each non-negative element by $2$ .

for (i = 0; i < n; i++)
  if (m[i] >= 0) m[i] = m[i] + 2;

Print the answer — the resulting array.

for (i = 0; i < n; i++)
  printf("%d ",m[i]);
printf("\n");

Algorithm implementation — vector, resize

Read the input data.

scanf("%d",&n);
m.resize(n);
for (i = 0; i < n; i++)
  scanf("%d",&m[i]);

Iterate through the elements of an array. Increase each non-negative element by $2$ .

for (i = 0; i < n; i++)
  if (m[i] >= 0) m[i] = m[i] + 2;

Print the answer — the resulting array.

for (i = 0; i < n; i++)
  printf("%d ",m[i]);
printf("\n");

Algorithm implementation — pointers

#include <stdio.h>

int i, n;
int *m;

int main(void)
{
  scanf("%d",&n);
  // allocate mamory
  m = new int[n];

  // read the array
  for (i = 0; i < n; i++)
    scanf("%d",&m[i]);

  // process the array
  for (i = 0; i < n; i++)
    if (m[i] >= 0) m[i] = m[i] + 2;

  // print the array
  for (i = 0; i < n; i++)
    printf("%d ",m[i]);
  printf("\n");

  // free the memory
  delete[] m;
  return 0;
}

Java implementation

import java.util.*;

public class Main 
{
  public static void main(String[] args) 
  {
    Scanner con = new Scanner(System.in);
    int n = con.nextInt();
    for (int i = 0; i < n; i++)
    {
      int val = con.nextInt();
      if (val >= 0) val += 2;
      System.out.print(val + " ");
    }
    System.out.println();
    con.close();
  }
}

Java implementation — array

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];
    for (int i = 0; i < n; i++)
      m[i] = con.nextInt();
    
    for (int i = 0; i < n; i++)
      if (m[i] >= 0) m[i] += 2;
    
    for (int i = 0; i < n; i++)
      System.out.print(m[i] + " ");
    System.out.println();
    con.close();
  }
}

Java implementation — ArrayList

import java.util.*;

public class Main 
{
  public static void main(String[] args) 
  {
    Scanner con = new Scanner(System.in);
    int n = con.nextInt();
    ArrayList<Integer> m = new ArrayList<Integer>(); 
    for (int i = 0; i < n; i++)
    {
      int val = con.nextInt();
      m.add(val);
    }
    
    for (int i = 0; i < n; i++)
      if (m.get(i) >= 0) m.set(i,m.get(i)+2);
    
    for (int i = 0; i < n; i++)
      System.out.print(m.get(i) + " ");
    System.out.println();
    con.close();
  }
}

Python implementation

Read the input data.

n = int(input())
lst = list(map(int,input().split()))

Iterate through the elements of a list. Increase each non-negative element by $2$ .

for i in range(n):
  if lst[i] >= 0:
    lst[i] = lst[i] + 2

Print the answer — the list $l s t$ .

print(*lst)

Python implementation — string

Read the input data.

n = int(input())
list = list(map(int,input().split()))
res = ""

Iterate through the elements of a list. Increase each non-negative element by $2$ .

for i in range(n):
  if list[i] >= 0:
    list[i] = list[i] + 2

Store the answer in the string $res$ .

  res = res + str(list[i])+ " "

Print the answer — the list $res$ .

print(res)

Python implementation — map

Read the input data.

n = int(input())
lst = map(int,input().split())

Declare a function $f$ defined as follows:

f (n) = {n + 2, n \geq 0 n, n < 0

def f(n):
  if n >= 0:
    return n + 2
  return n

Apply the function $f$ to each element of the list $l s t$ .

res = list(map(f,lst))

Print the list $res$ .

for x in res:
  print(x, end=" ")