Array compression and search in C++(basics) - c++

Question

So I need help with array of 20 elements.
I need to find each element Absolute value, and if it's value is less than 1 then remove this element from array. Afterwards at the end of array put 0 in place of a removed element.
So im looking for some functions which will help me to do this.
This is my code:
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int OddSumm(int arr[], int lenght)
{
int i,p,z;
p=0;
for (i=0; i<lenght; i++)
if(arr[i]%2!=0 && arr[i]!=0 ){
p+=arr[i];
}
return p;
}
int SummBetweenNegativeNumbers(int arr[], int lenght) {
int s,i,r,z;
s=0;
for (i=0; i<lenght; i++)
if(arr[i]<0){
i++;
r=i;
for (i=r; i<lenght; i++)
if(arr[i]<0){
--i;
z=i;
for (i=r; i<=z; i++)
s+=arr[i];
}
}
return s;
}
int main(int argc, char *argv[])
{
int var;
int i,arr[20];
int s,p,lenght;
lenght=20;
{
printf("Type in %d elements \n",lenght);
for (i=0; i<lenght; i++)
scanf("%d", &arr[i]);
}
p=OddSumm(arr,lenght);
s=SummBetweenNegativeNumbers(arr,lenght);
printf("\n\t 1a)Odd numbers summ: %d",p);
printf("\n\t 1b)Elements summ between negativ numbers: %d", s);
printf("\n\t 2)Compressed array: ");
for(i=lenght-1; i>=0; i--)
printf(" %d",arr[i]);
printf("\n\n");
system("pause");
return 0;
}

Answer 1

use std::transform to transform your data
use std::remove to compact these nonzeros
use std::fill to fill padding zeros
example code
#include <vector>
#include <cstdlib>
#include <iterator>
#include <algorithm>
#include <iostream>
int my_function(int value){
value = std::abs(value);
return value<1 ? 0:value;
}
int main()
{
int v[]={0,1,2,-4,-5,3};
std::transform(std::begin(v),std::end(v),std::begin(v),my_function);
auto end=std::remove(std::begin(v),std::end(v),0);
std::fill(end,std::end(v),0);
for(auto value : v)std::cout<<value<<' ';
}