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/
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// Author : Hao Chen
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// Date : 2014-08-22
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class Solution {
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public:
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int maxProfit(vector<int> &prices) {
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if (prices.size()<=1) return 0;
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int n = prices.size();
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vector<int> forward(n);
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forward[0] = 0;
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int lowestBuyInPrice = prices[0];
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for(int i=1; i<n; i++){
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forward[i] = max(forward[i-1], prices[i] - lowestBuyInPrice);
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lowestBuyInPrice = min(lowestBuyInPrice, prices[i]);
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}
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vector<int> backward(n);
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backward[n-1] = 0;
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int highestSellOutPrice = prices[n-1];
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for(int i=n-2; i>=0; i--){
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backward[i] = max(backward[i+1], highestSellOutPrice - prices[i]);
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highestSellOutPrice = max(highestSellOutPrice, prices[i]);
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}
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int max_profit = 0;
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for(int i=0; i<n; i++){
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max_profit = max(max_profit, forward[i]+backward[i]);
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}
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return max_profit;
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}
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};
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