Driving

#include <stdio.h> // include before iostream for faster scanf
#include <iostream>
#include <vector>
#include <string>
#include <map>
#include <unordered_map>
#include <algorithm>
#include <utility>
#include <set>
#include <unordered_set>
#include <cmath>
#include <math.h>
#include <queue>
#include <stdlib.h>
#include <string.h>
#include <sstream>
#include <tuple>
#include <utility>
#include <iomanip>
#include <iterator>

using namespace std;
typedef long long LL;

#define printv(printVec) for (auto printVecIter : (printVec)) cout << printVecIter << " "; cout << endl;

// g++-4.8 -Wall -Wshadow -std=c++11 a.cpp && ./a.out

int main() {
	std::ios::sync_with_stdio(false);cin.tie(0);
	LL n,p;
	cin >> n>>p;
	vector<LL> v(n);
	for (int i = 0; i < n; i++) cin >> v[i];
	LL ans = 0;
	sort(v.begin(), v.end());
	for (int i = 0; i < n; i++) {
		LL cur = p*(i+1);
		LL dist = v[i] - v[0];
		ans = max(ans, cur - dist);
	}
	cout << ans;
	
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED