37 lines
1.0 KiB
C++
37 lines
1.0 KiB
C++
|
// Source : https://oj.leetcode.com/problems/best-time-to-buy-and-sell-stock-iii/
|
||
|
|
// Author : Hao Chen
|
||
|
|
// Date : 2014-08-22
|
||
|
|
|
||
|
|
|
||
|
|
class Solution {
|
||
|
|
public:
|
||
|
|
int maxProfit(vector<int> &prices) {
|
||
|
|
if (prices.size()<=1) return 0;
|
||
|
|
|
||
|
|
int n = prices.size();
|
||
|
|
|
||
|
|
vector<int> forward(n);
|
||
|
|
forward[0] = 0;
|
||
|
|
int lowestBuyInPrice = prices[0];
|
||
|
|
for(int i=1; i<n; i++){
|
||
|
|
forward[i] = max(forward[i-1], prices[i] - lowestBuyInPrice);
|
||
|
|
lowestBuyInPrice = min(lowestBuyInPrice, prices[i]);
|
||
|
|
}
|
||
|
|
|
||
|
|
vector<int> backward(n);
|
||
|
|
backward[n-1] = 0;
|
||
|
|
int highestSellOutPrice = prices[n-1];
|
||
|
|
for(int i=n-2; i>=0; i--){
|
||
|
|
backward[i] = max(backward[i+1], highestSellOutPrice - prices[i]);
|
||
|
|
highestSellOutPrice = max(highestSellOutPrice, prices[i]);
|
||
|
|
}
|
||
|
|
|
||
|
|
int max_profit = 0;
|
||
|
|
for(int i=0; i<n; i++){
|
||
|
|
max_profit = max(max_profit, forward[i]+backward[i]);
|
||
|
|
}
|
||
|
|
|
||
|
|
return max_profit;
|
||
|
|
}
|
||
|
|
};
|