太酷啦

#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 << endl;
    return 0;
}