1185A - Ropewalkers - CodeForces Solution

#include <bits/stdc++.h>
using namespace std;

int main() {
	// your code goes here
	int a,b,c,d;
	cin>>a>>b>>c>>d;
	vector<int>v;
	v.push_back(a);
	v.push_back(b);
	v.push_back(c);
	int ct=0;
	sort(v.begin(),v.end());
	for(int i=0;i<v.size()-1;i++){
	    int ans=v[i+1]-v[i];
	    if(ans<d){
	        ct+=(d-ans);
	    }
	}
	cout<<ct<<endl;
	return 0;
}