我不明白为什么错了
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 3e5 + 10;
ll n, p[N], t[N], a[N], minx=-100000, maxx, sum, pre;
int main(){
freopen("arrange.in","r",stdin);
freopen("arrange.out","w",stdout);
cin >> n;
for(int i = 0; i < n; i++){
cin >> p[i];
}
for(int i = 0; i < n; i++){
cin >> t[i];
a[i] = p[i] - t[i];
}
pre = a[0];
for(int i = 1; i < n; i++){
if(a[i] > pre){
sum += (a[i] - pre);
}
pre = a[i];
}
cout << sum + a[0];
fclose(stdin);
fclose(stdout);
return 0;
}
