题解 | 买卖股票的最好时机(二)

#include <bits/stdc++.h>
using namespace std;

int main() {
    int n;
    cin >> n;
    if (n <= 1) {
        cout << 0 << '\n';
        return 0;
    }

    long long profit = 0;
    int prev, cur;
    cin >> prev;                   // 第一天价格
    for (int i = 1; i < n; ++i) {
        cin >> cur;                // 边读边算
        if (cur > prev) profit += (cur - prev);
        prev = cur;
    }
    cout << profit << '\n';
    return 0;
}