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Calculate cheapest way of buying gas in order to drive along a highway.

Programming language:
Spoken language:

There are N+1 towns numbered from 0 to N lying along a highway. The distances between towns, and gas prices in each town, are given. A truck has to deliver cargo from town 0 to town N. What is the cheapest way to buy enough gas for this trip?

Two non-empty zero-indexed arrays D (distances) and P (prices), each consisting of N positive integers, and a positive integer T (tank capacity) are given. Consider any zero-indexed sequence R (refill strategy) consisting of N non-negative integers (amount of fuel bought in each town).

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

The following conditions (meaning that the truck must not run out of fuel and cannot fill up with more fuel than its tank capacity) must hold:

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Sequence [15, 10, 2] is a refill strategy with cost 46. Sequence [10, 5, 12] is not a valid refill strategy, because the truck would run out of fuel between towns 1 and 2. Sequence [10, 15, 2] is a refill strategy with cost 41, and no cheaper refill strategy exists for this choice of arrays D, P and number T.

Write a function:

int solution(int D[], int P[], int N, int T);

that, given two non-empty zero-indexed arrays D and P consisting of N positive integers each and a positive integer T, returns the cost of the cheapest refill strategy for D, P and T.

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

Assume that:

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

Complexity:

- expected worst-case time complexity is O(N);
- expected worst-case space complexity is O(N), beyond input storage (not counting the storage required for input arguments).

Copyright 2009–2018 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.

There are N+1 towns numbered from 0 to N lying along a highway. The distances between towns, and gas prices in each town, are given. A truck has to deliver cargo from town 0 to town N. What is the cheapest way to buy enough gas for this trip?

Two non-empty zero-indexed arrays D (distances) and P (prices), each consisting of N positive integers, and a positive integer T (tank capacity) are given. Consider any zero-indexed sequence R (refill strategy) consisting of N non-negative integers (amount of fuel bought in each town).

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

The following conditions (meaning that the truck must not run out of fuel and cannot fill up with more fuel than its tank capacity) must hold:

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Sequence [15, 10, 2] is a refill strategy with cost 46. Sequence [10, 5, 12] is not a valid refill strategy, because the truck would run out of fuel between towns 1 and 2. Sequence [10, 15, 2] is a refill strategy with cost 41, and no cheaper refill strategy exists for this choice of arrays D, P and number T.

Write a function:

int solution(vector<int> &D, vector<int> &P, int T);

that, given two non-empty zero-indexed arrays D and P consisting of N positive integers each and a positive integer T, returns the cost of the cheapest refill strategy for D, P and T.

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

Assume that:

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

Complexity:

- expected worst-case time complexity is O(N);
- expected worst-case space complexity is O(N), beyond input storage (not counting the storage required for input arguments).

Copyright 2009–2018 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.

There are N+1 towns numbered from 0 to N lying along a highway. The distances between towns, and gas prices in each town, are given. A truck has to deliver cargo from town 0 to town N. What is the cheapest way to buy enough gas for this trip?

Two non-empty zero-indexed arrays D (distances) and P (prices), each consisting of N positive integers, and a positive integer T (tank capacity) are given. Consider any zero-indexed sequence R (refill strategy) consisting of N non-negative integers (amount of fuel bought in each town).

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

The following conditions (meaning that the truck must not run out of fuel and cannot fill up with more fuel than its tank capacity) must hold:

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Sequence [15, 10, 2] is a refill strategy with cost 46. Sequence [10, 5, 12] is not a valid refill strategy, because the truck would run out of fuel between towns 1 and 2. Sequence [10, 15, 2] is a refill strategy with cost 41, and no cheaper refill strategy exists for this choice of arrays D, P and number T.

Write a function:

class Solution { public int solution(int[] D, int[] P, int T); }

that, given two non-empty zero-indexed arrays D and P consisting of N positive integers each and a positive integer T, returns the cost of the cheapest refill strategy for D, P and T.

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

Assume that:

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

Complexity:

- expected worst-case time complexity is O(N);
- expected worst-case space complexity is O(N), beyond input storage (not counting the storage required for input arguments).

Copyright 2009–2018 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Write a function:

func Solution(D []int, P []int, T int) int

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

Assume that:

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

Complexity:

- expected worst-case time complexity is O(N);

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Write a function:

class Solution { public int solution(int[] D, int[] P, int T); }

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

Assume that:

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

Complexity:

- expected worst-case time complexity is O(N);

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Write a function:

function solution(D, P, T);

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

Assume that:

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

Complexity:

- expected worst-case time complexity is O(N);

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Write a function:

function solution(D, P, T)

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

Assume that:

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

Complexity:

- expected worst-case time complexity is O(N);

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Write a function:

int solution(NSMutableArray *D, NSMutableArray *P, int T);

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

Assume that:

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

Complexity:

- expected worst-case time complexity is O(N);

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Write a function:

function solution(D: array of longint; P: array of longint; N: longint; T: longint): longint;

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

Assume that:

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

Complexity:

- expected worst-case time complexity is O(N);

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Write a function:

function solution($D, $P, $T);

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

Assume that:

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

Complexity:

- expected worst-case time complexity is O(N);

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Write a function:

def solution(D, P, T)

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

Assume that:

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

Complexity:

- expected worst-case time complexity is O(N);

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Write a function:

def solution(d, p, t)

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

Assume that:

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

Complexity:

- expected worst-case time complexity is O(N);

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Write a function:

object Solution { def solution(d: Array[Int], p: Array[Int], t: Int): Int }

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

Assume that:

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

Complexity:

- expected worst-case time complexity is O(N);

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Write a function:

public func solution(inout D : [Int], inout _ P : [Int], _ T : Int) -> Int

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

Assume that:

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

Complexity:

- expected worst-case time complexity is O(N);

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Write a function:

public func solution(_ D : inout [Int], _ P : inout [Int], _ T : Int) -> Int

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

Assume that:

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

Complexity:

- expected worst-case time complexity is O(N);

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Write a function:

Private Function solution(D As Integer(), P As Integer(), T As Integer) As Integer

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

Assume that:

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

Complexity:

- expected worst-case time complexity is O(N);

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