/*
IOI2015 BOXES.CPP
*/
#include "boxes.h"
#include <vector>
#include <math.h>
#include <algorithm>
using namespace std;
#define ll long long
/*
Lemma:
this is dp and I will move on to q2 after getting the first subtask
[solved]
New Lemma:
the second subtask does not use dp.
hence I will only move on to q2 after solving the first two subtasks
[solved]
Even newer Lemma:
the third subtask is brute force.
brute force > dp
hence I will only move on to q2 after solving the first three subtasks
[solved]
Newest Lemma:
I think maybe some more why not
*/
vector<bool> haps;
ll gL;
ll dist(ll a, ll b){
ll A = max(a,b);
ll B = min(a,b);
return min(A-B, gL-A+B);
}
// pseudocode-ahh solution
// so goofy
long long delivery(int N, int K, int L, int p[]) {
gL = L;
// perhaps we can get 50...
// pick different places to start?
vector<int> ns(N);
for(int i=0; i<N; i++){
ns[i] = p[i];
}
ll ans = 10000000000000000;
ll nA;
int tS, tE;
for(int s=0; s<K; s++){
// different starting places...
nA=0;
for(int i=s; i<N; i+=K){
tS = i; // index of starting participant
tE = (i+s-1)%N; // index of ending participant
nA += dist(0, ns[tS]);
nA += dist(ns[tS], ns[tE]);
nA += dist(ns[tE], 0);
}
ans = min(ans, nA);
}
return ans;
}
