P5019 [NOIP 2018 提高组] 铺设道路

P5019 [NOIP 2018 提高组] 铺设道路 - 洛谷

代码：

#include <iostream>
using namespace std;const int MAX_N = 100010;
int a[MAX_N];int main() {int n;cin >> n;for (int i = 1; i <= n; ++i) {cin >> a[i];}long long ans = a[1]; for (int i = 2; i <= n; ++i) {if (a[i] > a[i-1]) {ans += a[i] - a[i-1];}}cout << ans << endl;return 0;
}