题解

欸，没人啊

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

int main() {
	int N;
	cin >> N;
	vector<int> p(N), t(N), d(N);
	for (int i = 0; i < N; ++i)
		cin >> p[i];
	for (int i = 0; i < N; ++i)
		cin >> t[i];
	for (int i = 0; i < N; ++i)
		d[i] = p[i] - t[i];
	int first_nonzero = 0, ans = 0;
	while (true) {
		while (first_nonzero < N && d[first_nonzero] == 0)
			++first_nonzero;
		if (first_nonzero == N)
			break;
		int r = first_nonzero;
		auto sgn = [&](int x) {
			if (x < 0)
				return -1;
			if (x > 0)
				return 1;
			return 0;
		};
		while (r + 1 < N && sgn(d[r + 1]) == sgn(d[first_nonzero]))
			++r;
		for (int i = first_nonzero; i <= r; ++i) {
			if (d[i] < 0)
				++d[i];
			else
				--d[i];
		}
		++ans;
	}
	cout << ans << "\n";
}