Description#
You are given an integer array prices where prices[i] is the price of the ith item in a shop.
There is a special discount for items in the shop. If you buy the ith item, then you will receive a discount equivalent to prices[j] where j is the minimum index such that j > i and prices[j] <= prices[i]. Otherwise, you will not receive any discount at all.
Return an integer array answer where answer[i] is the final price you will pay for the ith item of the shop, considering the special discount.
Example 1:
Input: prices = [8,4,6,2,3]
Output: [4,2,4,2,3]
Explanation:
For item 0 with price[0]=8 you will receive a discount equivalent to prices[1]=4, therefore, the final price you will pay is 8 - 4 = 4.
For item 1 with price[1]=4 you will receive a discount equivalent to prices[3]=2, therefore, the final price you will pay is 4 - 2 = 2.
For item 2 with price[2]=6 you will receive a discount equivalent to prices[3]=2, therefore, the final price you will pay is 6 - 2 = 4.
For items 3 and 4 you will not receive any discount at all.
Example 2:
Input: prices = [1,2,3,4,5]
Output: [1,2,3,4,5]
Explanation: In this case, for all items, you will not receive any discount at all.
Example 3:
Input: prices = [10,1,1,6]
Output: [9,0,1,6]
Constraints:
1 <= prices.length <= 5001 <= prices[i] <= 1000
Solutions#
Solution 1#
1
2
3
4
5
6
7
8
9
10
| class Solution:
def finalPrices(self, prices: List[int]) -> List[int]:
ans = []
for i, v in enumerate(prices):
ans.append(v)
for j in range(i + 1, len(prices)):
if prices[j] <= v:
ans[-1] -= prices[j]
break
return ans
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
| class Solution {
public int[] finalPrices(int[] prices) {
int n = prices.length;
int[] ans = new int[n];
for (int i = 0; i < n; ++i) {
ans[i] = prices[i];
for (int j = i + 1; j < n; ++j) {
if (prices[j] <= prices[i]) {
ans[i] -= prices[j];
break;
}
}
}
return ans;
}
}
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
| class Solution {
public:
vector<int> finalPrices(vector<int>& prices) {
int n = prices.size();
vector<int> ans(n);
for (int i = 0; i < n; ++i) {
ans[i] = prices[i];
for (int j = i + 1; j < n; ++j) {
if (prices[j] <= prices[i]) {
ans[i] -= prices[j];
break;
}
}
}
return ans;
}
};
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
| func finalPrices(prices []int) []int {
n := len(prices)
ans := make([]int, n)
for i, v := range prices {
ans[i] = v
for j := i + 1; j < n; j++ {
if prices[j] <= v {
ans[i] -= prices[j]
break
}
}
}
return ans
}
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
| function finalPrices(prices: number[]): number[] {
const n = prices.length;
const ans = new Array(n);
for (let i = 0; i < n; ++i) {
ans[i] = prices[i];
for (let j = i + 1; j < n; ++j) {
if (prices[j] <= prices[i]) {
ans[i] -= prices[j];
break;
}
}
}
return ans;
}
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
| impl Solution {
pub fn final_prices(prices: Vec<i32>) -> Vec<i32> {
let n = prices.len();
let mut stack = Vec::new();
let mut res = vec![0; n];
for i in (0..n).rev() {
let price = prices[i];
while !stack.is_empty() && *stack.last().unwrap() > price {
stack.pop();
}
res[i] = price - stack.last().unwrap_or(&0);
stack.push(price);
}
res
}
}
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
| /**
* @param {number[]} prices
* @return {number[]}
*/
var finalPrices = function (prices) {
for (let i = 0; i < prices.length; i++) {
for (let j = i + 1; j < prices.length; j++) {
if (prices[i] >= prices[j]) {
prices[i] -= prices[j];
break;
}
}
}
return prices;
};
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
| class Solution {
/**
* @param Integer[] $prices
* @return Integer[]
*/
function finalPrices($prices) {
for ($i = 0; $i < count($prices); $i++) {
for ($j = $i + 1; $j < count($prices); $j++) {
if ($prices[$i] >= $prices[$j]) {
$prices[$i] -= $prices[$j];
break;
}
}
}
return $prices;
}
}
|
Solution 2#
1
2
3
4
5
6
7
8
9
| class Solution:
def finalPrices(self, prices: List[int]) -> List[int]:
stk = []
ans = prices[:]
for i, v in enumerate(prices):
while stk and prices[stk[-1]] >= v:
ans[stk.pop()] -= v
stk.append(i)
return ans
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
| class Solution {
public int[] finalPrices(int[] prices) {
Deque<Integer> stk = new ArrayDeque<>();
int n = prices.length;
int[] ans = new int[n];
for (int i = 0; i < n; ++i) {
ans[i] = prices[i];
while (!stk.isEmpty() && prices[stk.peek()] >= prices[i]) {
ans[stk.pop()] -= prices[i];
}
stk.push(i);
}
return ans;
}
}
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
| class Solution {
public:
vector<int> finalPrices(vector<int>& prices) {
stack<int> stk;
vector<int> ans = prices;
for (int i = 0; i < prices.size(); ++i) {
while (!stk.empty() && prices[stk.top()] >= prices[i]) {
ans[stk.top()] -= prices[i];
stk.pop();
}
stk.push(i);
}
return ans;
}
};
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
| func finalPrices(prices []int) []int {
var stk []int
n := len(prices)
ans := make([]int, n)
for i, v := range prices {
ans[i] = v
for len(stk) > 0 && prices[stk[len(stk)-1]] >= v {
ans[stk[len(stk)-1]] -= v
stk = stk[:len(stk)-1]
}
stk = append(stk, i)
}
return ans
}
|
1
2
3
4
5
6
7
8
9
10
11
12
13
| function finalPrices(prices: number[]): number[] {
const n = prices.length;
const stk = [];
const ans = new Array(n);
for (let i = 0; i < n; ++i) {
ans[i] = prices[i];
while (stk.length && prices[stk[stk.length - 1]] >= prices[i]) {
ans[stk.pop()] -= prices[i];
}
stk.push(i);
}
return ans;
}
|
Solution 3#
1
2
3
4
5
6
7
8
9
10
11
| class Solution:
def finalPrices(self, prices: List[int]) -> List[int]:
stk = []
ans = prices[:]
for i in range(len(prices) - 1, -1, -1):
while stk and prices[stk[-1]] > prices[i]:
stk.pop()
if stk:
ans[i] -= prices[stk[-1]]
stk.append(i)
return ans
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
| class Solution {
public int[] finalPrices(int[] prices) {
Deque<Integer> stk = new ArrayDeque<>();
int n = prices.length;
int[] ans = new int[n];
for (int i = n - 1; i >= 0; --i) {
ans[i] = prices[i];
while (!stk.isEmpty() && prices[stk.peek()] > prices[i]) {
stk.pop();
}
if (!stk.isEmpty()) {
ans[i] -= prices[stk.peek()];
}
stk.push(i);
}
return ans;
}
}
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
| class Solution {
public:
vector<int> finalPrices(vector<int>& prices) {
stack<int> stk;
int n = prices.size();
vector<int> ans(n);
for (int i = n - 1; i >= 0; --i) {
ans[i] = prices[i];
while (!stk.empty() && prices[stk.top()] > prices[i]) {
stk.pop();
}
if (!stk.empty()) {
ans[i] -= prices[stk.top()];
}
stk.push(i);
}
return ans;
}
};
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
| func finalPrices(prices []int) []int {
stk := []int{}
n := len(prices)
ans := make([]int, n)
for i := n - 1; i >= 0; i-- {
ans[i] = prices[i]
for len(stk) > 0 && prices[stk[len(stk)-1]] > prices[i] {
stk = stk[:len(stk)-1]
}
if len(stk) > 0 {
ans[i] -= prices[stk[len(stk)-1]]
}
stk = append(stk, i)
}
return ans
}
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
| function finalPrices(prices: number[]): number[] {
const n = prices.length;
const stack = [];
const res = new Array(n);
for (let i = n - 1; i >= 0; i--) {
const price = prices[i];
while (stack.length !== 0 && stack[stack.length - 1] > price) {
stack.pop();
}
res[i] = price - (stack[stack.length - 1] ?? 0);
stack.push(price);
}
return res;
}
|
