请问我的J题这样写为啥通不过呀（我是萌新别喷我┭┮﹏┭┮）
#include<bits/stdc++.h>
using namespace std;
int main()
{
int n;
cin>>n;
vector<char> str(n);
for (int i = 0; i < n; ++i)
cin >> str[i];
int sum = 0,speed = 0;
for(int i = 0;i < n;i++)
{
if(str[i] == '0')
{
speed += 10;
sum += speed;
}
if(str[i] == '1')
{
speed -= 5;
if(speed < 0) speed = 0;
sum += speed;
}
if(str[i] == '2')
{
int temp = speed;
speed = max(0, speed - 10);
sum += speed;
speed = temp;
}
}
cout<<sum<<endl;
return 0;
}
