class Solution {
public int maxProfit(int[] prices) {
int n = prices.length;
if (n == 0) return 0;
int[][] dp = new int[n][2];
// dp[i][0] : noShare
// dp[i][1] : withShare
dp[0][1] = -prices[0];
for (int i = 1; i < n; i++) {
dp[i][0] = Math.max(dp[i - 1][0], dp[i - 1][1] + prices[i]);
dp[i][1] = Math.max(dp[i - 1][1], dp[i - 1][0] - prices[i]);
}
return dp[n - 1][0];
}
}
class Solution {
public int maxProfit(int[] prices) {
int n = prices.length;
if (n == 0) return 0;
int noShare = 0;
int withShare = -prices[0];
for (int i = 1; i < n; i++) {
noShare = Math.max(noShare, withShare + prices[i]);
withShare = Math.max(withShare, noShare - prices[i]);
}
return noShare;
}
}