Best time to buy and sell stock 3

Problem:

Say you have an array for which the i^th element is the price of a given stock on day i.

Design an algorithm to find the maximum profit. You may complete at most two transactions.

Note:
You may not engage in multiple transactions at the same time (ie, you must sell the stock before you buy again).

Solution:

class Solution {
public:
    int maxProfit(vector<int> &array) {
    int n = array.size();
if (n < 2)
return 0;

int forward[n], backward[n], min_so_far, max_so_far, ret = 0;
min_so_far = array[0];
max_so_far = array[n - 1];
        forward[0] = 0;
        backward[n-1] = 0;

for (int i = 1; i < n; i++) {
if (array[i] >= min_so_far) {
forward[i] = max(forward[i-1], array[i] - min_so_far);
} else {
min_so_far = array[i];
forward[i] = forward[i-1];
}
}

for (int i = n - 2; i >= 0; i--) {
if (array[i] <= max_so_far) {
backward[i] = max(backward[i+1], max_so_far - array[i]);
} else {
max_so_far = array[i];
backward[i] = backward[i+1];
}
}

for (int i = 0; i < n; i++) {
ret = max(forward[i] + backward[i], ret);
}
return ret;
}
};