1791E - Negatives and Positives - CodeForces Solution

#include <bits/stdc++.h>
using namespace std;
long long  solve(vector<int> &v,int n)
{
    long long sum=0,flag=0,neg=0,mini=1e10;
    for(int i=0;i<n;i++)
    {
        sum+=abs(v[i]);
        mini=min(1LL*abs(v[i]),mini);
        if(v[i]<0)
        neg++;
        else if(v[i]==0)
        flag=1;
    }
    if(neg%2==0 || flag==1)
    return sum;
    return sum-2*1LL*mini;
}
int main() {
	int t;
	cin>>t;
	while(t--)
	{
	    int n;
	    cin>>n;
	    vector<int> v(n);
	    for(int i=0;i<n;i++)
	    {
	        cin>>v[i];
	    }
	    cout<<solve(v,n)<<endl;
	}
	return 0;
}