LeetCode 75

Best Time to Buy and Sell Stock III

Problem
LC 123
Topic
DP Multidim
File
official75_LC123BestTimeToBuyAndSellStockIII.java
Path
pkg5leetcode/official75/official75_LC123BestTimeToBuyAndSellStockIII.java
Package
pkg5leetcode.official75
Command
java pkg5leetcode/official75/official75_LC123BestTimeToBuyAndSellStockIII.java
Approach
DP track profit after 0/1/2 transactions.
Complexity
Time O(n), Space O(1)

LeetCode solutions

There is no in-browser runner. This is the file from the curriculum, unchanged.

pkg5leetcode/official75/official75_LC123BestTimeToBuyAndSellStockIII.java
1package pkg5leetcode.official75;2 3/*4 * Best Time to Buy and Sell Stock III | LC 1235 * APPROACH: DP track profit after 0/1/2 transactions.6 * COMPLEXITY: Time O(n), Space O(1)7 */8public class official75_LC123BestTimeToBuyAndSellStockIII {9    static int maxProfit(int[] prices) {10        int buy1 = Integer.MIN_VALUE / 2, sell1 = 0;11        int buy2 = Integer.MIN_VALUE / 2, sell2 = 0;12        for (int p : prices) {13            buy1 = Math.max(buy1, -p);14            sell1 = Math.max(sell1, buy1 + p);15            buy2 = Math.max(buy2, sell1 - p);16            sell2 = Math.max(sell2, buy2 + p);17        }18        return sell2;19    }20 21    public static void main(String[] args) {22        check(maxProfit(new int[]{3,3,5,0,0,3,1,4}) == 6, "case1");23        check(maxProfit(new int[]{1,2,3,4,5}) == 4, "case2");24        System.out.println("all tests passed");25    }26 27    static void check(boolean cond, String name) {28        if (!cond) throw new AssertionError("FAILED: " + name);29        System.out.println("  PASS " + name);30    }31}